remove avconv from Doxyfile

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Doxyfile

@@ -631,8 +631,7 @@ EXCLUDE_SYMLINKS       = NO
 # for example use the pattern */test/*
 
 EXCLUDE_PATTERNS       = *.git \
-                         *.d \
-                         avconv.c
+                         *.d
 
 # The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
 # (namespaces, classes, functions, etc.) that should be excluded from the