fix servertest in out of tree builds

Originally committed as revision 13631 to svn://svn.ffmpeg.org/ffmpeg/trunk

tests/server-regression.sh

@@ -9,7 +9,7 @@ mkdir -p tests/data
 FILES=`sed -n 's/^[^#]*<Stream \(.*\)>.*/\1/p' $2 | grep -v html`
 
 rm -f tests/feed1.ffm
-./ffserver -d -f tests/test.conf 2> /dev/null &
+./ffserver -d -f "$2" 2> /dev/null &
 FFSERVER_PID=$!
 echo "Waiting for feeds to startup..."
 sleep 2