avformat: Remove async from TESTPROGS

It is current disabled.
Signed-off-by: NDerek Buitenhuis <derek.buitenhuis@gmail.com>

libavformat/Makefile

@@ -566,10 +566,10 @@ SLIBOBJS-$(HAVE_GNU_WINDRES)             += avformatres.o
 SKIPHEADERS-$(CONFIG_FFRTMPCRYPT_PROTOCOL) += rtmpdh.h
 SKIPHEADERS-$(CONFIG_NETWORK)            += network.h rtsp.h
 
-TESTPROGS = async                                                       \
-            seek                                                        \
+TESTPROGS = seek                                                        \
             srtp                                                        \
             url                                                         \
+#           async                                                       \
 
 TESTPROGS-$(CONFIG_MOV_MUXER)            += movenc
 TESTPROGS-$(CONFIG_NETWORK)              += noproxy