Remove no longer needed fallback path.

Author: emmatyping

mypy/build.py

@@ -407,9 +407,6 @@ def default_lib_path(data_dir: str,
             if os.path.isdir(stubdir):
                 path.append(stubdir)
 
-    # Add fallback path that can be used if we have a broken installation.
-    if sys.platform != 'win32':
-        path.append('/usr/local/lib/mypy')
     if not path:
         print("Could not resolve typeshed subdirectories. If you are using mypy\n"
               "from source, you need to run \"git submodule update --init\".\n"