configure.ac: remove pcap check

libpcap isn't used in osmo-sgsn

Change-Id: I47880dba1f6855f31b5b6481eeb1027abc2a2671
diff --git a/configure.ac b/configure.ac
index a1dbce5..225a534 100644
--- a/configure.ac
+++ b/configure.ac
@@ -80,10 +80,6 @@
 dnl checks for header files
 AC_HEADER_STDC
 
-found_pcap=yes
-AC_CHECK_HEADERS(pcap/pcap.h,,found_pcap=no)
-AM_CONDITIONAL(HAVE_PCAP, test "$found_pcap" = yes)
-
 found_cdk=yes
 AC_CHECK_HEADERS(cdk/cdk.h,,found_cdk=no)
 AM_CONDITIONAL(HAVE_LIBCDK, test "$found_cdk" = yes)