Remove fix-project-settings.rb references from Makefile

Motivation:

The Makefile referenced a file which no longer exists.

Modifications:

Remove references to that file.

Result:

More happy project generation.

Author: glbrntt

Makefile

@@ -47,8 +47,6 @@ project: ${XCODEPROJ}
 
 ${XCODEPROJ}:
 	${SWIFT_PACKAGE} generate-xcodeproj --output $@
-	@-ruby fix-project-settings.rb GRPC.xcodeproj || \
-		echo "Consider running 'sudo gem install xcodeproj' to automatically set correct indentation settings for the generated project."
 
 # Generates LinuxMain.swift, only on macOS.
 generate-linuxmain: