avconv: fix -copyinkf.

This option only applies to streamcopy, but is currently processed only
when encoding.

avconv.c

@@ -3618,13 +3618,13 @@ static OutputStream *new_video_stream(OptionsContext *o, AVFormatContext *oc)
         ost->top_field_first = -1;
         MATCH_PER_STREAM_OPT(top_field_first, i, ost->top_field_first, oc, st);
 
-        MATCH_PER_STREAM_OPT(copy_initial_nonkeyframes, i, ost->copy_initial_nonkeyframes, oc ,st);
-
 #if CONFIG_AVFILTER
         MATCH_PER_STREAM_OPT(filters, str, filters, oc, st);
         if (filters)
             ost->avfilter = av_strdup(filters);
 #endif
+    } else {
+        MATCH_PER_STREAM_OPT(copy_initial_nonkeyframes, i, ost->copy_initial_nonkeyframes, oc ,st);
     }
 
     return ost;