turned on allow-app-extensions-only flag (#277)

Author: jaeopt

OptimizelySwiftSDK.xcodeproj/project.pbxproj

@@ -3917,6 +3917,7 @@
 		6E614DDE21E3F38A005982A1 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;
@@ -3943,6 +3944,7 @@
 		6E614DDF21E3F38A005982A1 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;
@@ -4314,6 +4316,7 @@
 		6EBAEB7D21E3FEF900D13AA9 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;
@@ -4339,6 +4342,7 @@
 		6EBAEB7E21E3FEF900D13AA9 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
+				APPLICATION_EXTENSION_API_ONLY = YES;
 				CODE_SIGN_IDENTITY = "";
 				CODE_SIGN_STYLE = Automatic;
 				DEFINES_MODULE = YES;