[thrift_protocol] need negative testing for default inclusion

Reviewed By: dweatherford
Test Plan: dev026 build


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665319 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/php/src/ext/thrift_protocol/config.m4 b/lib/php/src/ext/thrift_protocol/config.m4
index 1b03819..b5932f5 100644
--- a/lib/php/src/ext/thrift_protocol/config.m4
+++ b/lib/php/src/ext/thrift_protocol/config.m4
@@ -1,7 +1,7 @@
 PHP_ARG_ENABLE(thrift_protocol, whether to enable the thrift_protocol extension,
 [  --enable-thrift_protocol	Enable the fbthrift_protocol extension])
 
-if test "$PHP_THRIFT_PROTOCOL" == "yes"; then
+if test "$PHP_THRIFT_PROTOCOL" != "no"; then
   PHP_REQUIRE_CXX()
   PHP_NEW_EXTENSION(thrift_protocol, php_thrift_protocol.cpp, $ext_shared)
 fi