Fix the build when using igraph >= 0.10.
Retrieved from: https://sourceforge.net/p/rankwidth/tickets/2/.

--- rw-0.9/simplerw.c.newigraph 2017-02-14 00:20:35.000000000 +0900
+++ rw-0.9/simplerw.c   2022-09-11 19:39:47.033917305 +0900
@@ -134,7 +134,11 @@ int read_graph(const char *format, const
 		igraph_destroy(&igraph);
 		return(-1);
 	}
+#if (IGRAPH_VERSION_MAJOR >= 1) || ((IGRAPH_VERSION_MAJOR == 0) && (IGRAPH_VERSION_MINOR >= 10))
+	igraph_get_adjacency(&igraph, &imatrix, IGRAPH_GET_ADJACENCY_BOTH, NULL, IGRAPH_LOOPS_ONCE);
+#else
 	igraph_get_adjacency(&igraph, &imatrix, IGRAPH_GET_ADJACENCY_BOTH, 0);
+#endif
 	igraph_destroy(&igraph);
 	if(igraph_matrix_nrow(&imatrix) > MAX_VERTICES)
 	{
his.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=55483dcb985363af2d266e95eec7837c44ad4185'>refs</a><a class='active' href='/guix/log/tests/swh.scm'>log</a><a href='/guix/tree/tests/swh.scm?id=55483dcb985363af2d266e95eec7837c44ad4185'>tree</a><a href='/guix/commit/tests/swh.scm?id=55483dcb985363af2d266e95eec7837c44ad4185'>commit</a><a href='/guix/diff/tests/swh.scm?id=55483dcb985363af2d266e95eec7837c44ad4185'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/swh.scm'>
<input type='hidden' name='id' value='55483dcb985363af2d266e95eec7837c44ad4185'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<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=55483dcb985363af2d266e95eec7837c44ad4185'>root</a>/<a href='/guix/log/tests?id=55483dcb985363af2d266e95eec7837c44ad4185'>tests</a>/<a href='/guix/log/tests/swh.scm?id=55483dcb985363af2d266e95eec7837c44ad4185'>swh.scm</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/tests/swh.scm?id=55483dcb985363af2d266e95eec7837c44ad4185&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-01-21 11:22:08 +0100'>2021-01-21</span></td><td><a href='/guix/commit/tests/swh.scm?id=5225732b9b54ffa92b9d199246b87dae666a3f77'>swh: Test proper handling of null visit snapshot URL.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-12-21 17:47:35 +0100'>2020-12-21</span></td><td><a href='/guix/commit/tests/swh.scm?id=9608f4003dedd8dfe99327c15668ca1a43ebd93b'>tests: Fix malformed JSON.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>