Include feedback source in the core library source list

src/Makefile.am

@@ -110,8 +110,6 @@ utun_CORE_SOURCES = \
 	chat/chat_msg.c \
 	chat/chat_feedback.c \
 	chat/chat_feedback.h \
-	chat/chat_feedback.c \
-	chat/chat_feedback.h \
 	chat/chat_whisper.c \
 	chat/chat_channel.c \
 	chat/chat_profile.c \
@@ -246,6 +244,8 @@ libutun_a_SOURCES = \
 	chat/chat_core.c \
 	chat/chat_member.c \
 	chat/chat_msg.c \
+	chat/chat_feedback.c \
+	chat/chat_feedback.h \
 	chat/chat_channel.c \
 	chat/chat_profile.c \
 	chat/group_avatar.c \