Revert to Xcode default optimization level

Author: EduardoMolina

SU2_IDE/Xcode/SU2_CFD.xcodeproj/project.pbxproj

@@ -2630,7 +2630,6 @@
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_NO_COMMON_BLOCKS = YES;
-				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
 				GCC_WARN_SHADOW = YES;