pidgin-otr: Silence no-extra-portability warnings

Make it build with OE, was not building with warning turned on

Upstream-Status: Pending

Signed-off-by: Jakob Drexel <jake42@rommel.stw.uni-erlangen.de>

--- a/configure.ac	2012-09-01 17:03:19.000000000 +0200
+++ b/configure.ac	2014-01-12 21:59:24.920300215 +0100
@@ -4,7 +4,7 @@
 
 AM_CONFIG_HEADER(config.h)
 
-AM_INIT_AUTOMAKE([-Wall -Werror])
+AM_INIT_AUTOMAKE([-Wall -Werror -Wno-extra-portability])
 
 AC_PROG_CC