tool_main: turn off MinGW CRT's globbing

By default, the MinGW CRT globs command-line arguments. This prevents
getting a single asterisk into an argument as test 1299 does. Turn off
globbing by setting the global variable _CRT_glob to 0 for MinGW.

Fixes https://github.com/curl/curl/issues/1751
Closes https://github.com/curl/curl/pull/1813