build: use net-snmp-config to configure NetSNMP
The correct method to link to NetSNMP is to use net-snmp-config (which
is like pkg-config). Explicit link to libcrypto is also dropped
(NetSNMP libs are linked to libcrypto, no need to link Quagga to
it). Moreover, @SNMP_INCLUDES@ is dropped because useless. Due to a
bug in configure.ac, it was properly populated.
diff --git a/zebra/Makefile.am b/zebra/Makefile.am
index e5b749a..9ac90f8 100644
--- a/zebra/Makefile.am
+++ b/zebra/Makefile.am
@@ -1,6 +1,6 @@
## Process this file with automake to produce Makefile.in.
-INCLUDES = @INCLUDES@ -I.. -I$(top_srcdir) -I$(top_srcdir)/lib -I$(top_builddir)/lib @SNMP_INCLUDES@
+INCLUDES = @INCLUDES@ -I.. -I$(top_srcdir) -I$(top_srcdir)/lib -I$(top_builddir)/lib
DEFS = @DEFS@ -DSYSCONFDIR=\"$(sysconfdir)/\" -DMULTIPATH_NUM=@MULTIPATH_NUM@
INSTALL_SDATA=@INSTALL@ -m 600