[rygel] Build the gstreamer media-engine with -lm

[Jens Georg <jensgeorg src gnome org>]

commit 8f8154a001548f67c83c3941c1f535efbcbd1b96
Author: Sebastien Bacher <seb128 debian org>
Date:   Fri Aug 23 14:19:21 2019 +0000

    Build the gstreamer media-engine with -lm
    
    https://gitlab.gnome.org/GNOME/rygel/issues/142

 src/media-engines/gstreamer/Makefile.am | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/media-engines/gstreamer/Makefile.am b/src/media-engines/gstreamer/Makefile.am
index 466bc22f..b5c1b3ea 100644
--- a/src/media-engines/gstreamer/Makefile.am
+++ b/src/media-engines/gstreamer/Makefile.am
@@ -33,7 +33,8 @@ librygel_media_engine_gst_la_CFLAGS = \
 
 librygel_media_engine_gst_la_LIBADD = \
        $(RYGEL_MEDIA_ENGINE_GSTREAMER_DEPS_LIBS) \
-       $(RYGEL_COMMON_LIBRYGEL_SERVER_LIBS)
+       $(RYGEL_COMMON_LIBRYGEL_SERVER_LIBS) \
+    -lm
 
 librygel_media_engine_gst_la_LDFLAGS = \
        $(RYGEL_ENGINE_LINKER_FLAGS)