Makefile.defs: -DWITH_AS_SUPPORT is on by default

- it was for kamailio flavour only
- can be disabled with WITHAS=0 and exclude_modules+=seas
(cherry picked from commit 01cbe8bf98d6ad1ef8cf7e0b9f646fde81831fc6)

Makefile.defs

@@ -148,13 +148,14 @@ CFG_NAME=kamailio
 KMSTATS ?= 1
 # fast malloc statistics on
 FMSTATS ?= 1
-# application server support on
-WITHAS ?= 1
 else # unknown:
 # main binary name
 MAIN_NAME=kamailio
 endif
 
+# application server support on
+WITHAS ?= 1
+
 # what to install
 INSTALL_FLAVOUR=$(FLAVOUR)