hamlib: disable RPC backends to fix some more build breakages

Signed-off-by: Steven Barth <steven@midlink.org>

utils/hamlib/Makefile

@@ -8,7 +8,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=hamlib
 PKG_VERSION:=1.2.15.3
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 PKG_MD5SUM:=3cad8987e995a00e5e9d360e2be0eb43
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
@@ -295,6 +295,7 @@ endef
 CONFIGURE_ARGS+= \
 	--without-cxx-binding \
 	--without-winradio \
+	--without-rpc-backends \
 	--with-pic \
 
 define Package/hamlib/install