Avoid a type mismatch that shows up in C++11.
Taken from <https://bugs.debian.org/853560>.

--- a/src/rtphint.cpp	2012-05-20 16:11:53.000000000 -0600
+++ b/src/rtphint.cpp	2017-05-16 10:25:26.930705191 -0600
@@ -339,7 +339,7 @@
                 pSlash = strchr(pSlash, '/');
                 if (pSlash != NULL) {
                     pSlash++;
-                    if (pSlash != '\0') {
+                    if (*pSlash != '\0') {
                         length = (uint32_t)strlen(pRtpMap) - (pSlash - pRtpMap);
                         *ppEncodingParams = (char *)MP4Calloc(length + 1);
                         strncpy(*ppEncodingParams, pSlash, length);
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<div class='path'>path: <a href='/guix/log/?id=986e9025a5232155e2b1deb2db15229c302d921a'>root</a>/<a href='/guix/log/CODE-OF-CONDUCT?id=986e9025a5232155e2b1deb2db15229c302d921a'>CODE-OF-CONDUCT</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/CODE-OF-CONDUCT?id=986e9025a5232155e2b1deb2db15229c302d921a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-05-29 18:29:36 +0200'>2018-05-29</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=a076f19908d06b6df49f1c25c40de8838213cd71'>CODE-OF-CONDUCT: Switch to version 1.4 of the Contributor Covenant.</a><span class='msg-avail'>...<span class='msg-tooltip'>See the discussion at
&lt;https://lists.gnu.org/archive/html/guix-devel/2018-05/msg00146.html&gt;.

* CODE-OF-CONDUCT: Adapt from version 1.4 of the Contributor Covenant.
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