Eliminate doctor warning about paths with spaces (#14614)

Some people call me the space cowboy
Some people call me the gangster of love
Some people call me Maurice

packages/flutter_tools/lib/src/doctor.dart

@@ -231,13 +231,6 @@ class _FlutterValidator extends DoctorValidator {
     final FlutterVersion version = FlutterVersion.instance;
 
     messages.add(new ValidationMessage('Flutter version ${version.frameworkVersion} at ${Cache.flutterRoot}'));
-    if (Cache.flutterRoot.contains(' ')) {
-      messages.add(new ValidationMessage.error(
-        'Flutter SDK install paths with spaces are not yet supported. '
-        '(https://github.com/flutter/flutter/issues/6577)\n'
-        'Please move the SDK to a path that does not include spaces.'
-      ));
-    }
     messages.add(new ValidationMessage(
       'Framework revision ${version.frameworkRevisionShort} '
       '(${version.frameworkAge}), ${version.frameworkDate}'