avformat/ipfsgateway: fix capitalizaton mistake

Fix the incorrect capitalization of the project name in a comment.
The project is named FFmpeg, not FFMpeg.

Signed-off-by: Leo Izen <leo.izen@gmail.com>

libavformat/ipfsgateway.c

@@ -290,7 +290,7 @@ static int translate_ipfs_to_http(URLContext *h, const char *uri, int flags, AVD
         goto err;
     }
 
-    // Pass the URL back to FFMpeg's protocol handler.
+    // Pass the URL back to FFmpeg's protocol handler.
     ret = ffurl_open_whitelist(&c->inner, fulluri, flags,
                                &h->interrupt_callback, options,
                                h->protocol_whitelist,