fix solaris build

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@15062 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/spandsp/configure.gnu

 #! /bin/sh
-./configure "$@" --disable-shared --with-pic --enable-builtin-tiff
+./configure "`echo $@ | sed 's| -xC | |'`" --disable-shared --with-pic --enable-builtin-tiff