Taken from debian.

# Description: Disable update check by default.
Index: calibre/src/calibre/gui2/main.py
===================================================================
--- calibre.orig/src/calibre/gui2/main.py	2014-02-02 10:41:28.470954623 +0100
+++ calibre/src/calibre/gui2/main.py	2014-02-02 10:41:56.546954247 +0100
@@ -37,8 +37,8 @@
                       help=_('Start minimized to system tray.'))
     parser.add_option('-v', '--verbose', default=0, action='count',
                       help=_('Ignored, do not use. Present only for legacy reasons'))
-    parser.add_option('--no-update-check', default=False, action='store_true',
-            help=_('Do not check for updates'))
+    parser.add_option('--update-check', dest='no_update_check', default=True, action='store_false',
+            help=_('Check for updates'))
     parser.add_option('--ignore-plugins', default=False, action='store_true',
             help=_('Ignore custom plugins, useful if you installed a plugin'
                 ' that is preventing calibre from starting'))
/'>summary</a><a href='/guix/refs/?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>refs</a><a class='active' href='/guix/log/etc/completion/fish'>log</a><a href='/guix/tree/etc/completion/fish?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>tree</a><a href='/guix/commit/etc/completion/fish?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>commit</a><a href='/guix/diff/etc/completion/fish?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/completion/fish'>
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<option value='grep'>log msg</option>
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<option value='committer'>committer</option>
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<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>root</a>/<a href='/guix/log/etc?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>etc</a>/<a href='/guix/log/etc/completion?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>completion</a>/<a href='/guix/log/etc/completion/fish?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2'>fish</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/completion/fish?id=7ee5881dc16655f682449b3ac60a8e3b900e03a2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-03-20 17:17:58 +0100'>2018-03-20</span></td><td><a href='/guix/commit/etc/completion/fish?id=4a78fd4617908546be15d2c101f5cab512c71f8e'>Correct name and Email for ng0.</a><span class='msg-avail'>...</span></td><td>ng0</td></tr>
<tr><td><span title='2018-01-16 16:00:20 +0100'>2018-01-16</span></td><td><a href='/guix/commit/etc/completion/fish?id=b83fc85f9f40d9a5dff5b0d3ef38c1b93bd4c7e3'>etc: Add completions for fish.</a><span class='msg-avail'>...</span></td><td>ng0</td></tr>