ipa: Remove unneeded #include statement

Change-Id: I69f2891a2bea6f87f079b6778aa01ee27a25001b
diff --git a/src/gsm/ipa.c b/src/gsm/ipa.c
index f44c328..6dc3ab6 100644
--- a/src/gsm/ipa.c
+++ b/src/gsm/ipa.c
@@ -28,7 +28,6 @@
 
 #include <arpa/inet.h>
 #include <sys/types.h>
-#include <sys/socket.h>
 
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/talloc.h>