fix build: remove obsolete gtphub EXTRA_DIST.

Sponsored-by: On-Waves ehi
diff --git a/openbsc/tests/gtphub/Makefile.am b/openbsc/tests/gtphub/Makefile.am
index d818811..59480ed 100644
--- a/openbsc/tests/gtphub/Makefile.am
+++ b/openbsc/tests/gtphub/Makefile.am
@@ -2,10 +2,7 @@
 AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS)
 
 EXTRA_DIST = \
-	gtphub_test.ok \
-	gtphub_nc_test.sh \
-	gtphub_nc_test.ok \
-	hex2bin.py
+	gtphub_test.ok
 
 noinst_PROGRAMS = gtphub_test