move openbsc.pc to osmo-sgsn.pc

Change-Id: Iad28d85b2a6d175cbe5d506aa82e7e4d94111eff
diff --git a/configure.ac b/configure.ac
index aa1c0a1..55aa7d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -178,7 +178,7 @@
 AM_CONFIG_HEADER(bscconfig.h)
 
 AC_OUTPUT(
-    openbsc.pc
+    osmo-sgsn.pc
     include/openbsc/Makefile
     include/Makefile
     src/Makefile