Enable for use in application extensions

Reachability.xcodeproj/project.pbxproj

@@ -364,6 +364,7 @@
 		AA7344871BE7678B008AFE69 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;
@@ -383,6 +384,7 @@
 		AA7344881BE7678B008AFE69 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CLANG_ENABLE_MODULES = YES;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;