Fix the git URL regex which may incorrectly match a Windows path as git URL

E.g. c:/temp/pytest-of-Screamer/pytest-8/test_import_after_add_git1_0/test3.git

Author: screamerbg

mbed/mbed.py

@@ -105,7 +105,7 @@
 regex_url_ref = r'^(.*/([\w.+-]+)(?:\.\w+)?)/?(?:#(.*))?$'
 
 # git url (no #rev)
-regex_git_url = r'^(git\://|ssh\://|https?\://|)(([^/:@]+)(\:([^/:@]+))?@)?([^/:]+)[:/](.+?)(\.git|\/?)$'
+regex_git_url = r'^(git\://|ssh\://|https?\://|)(([^/:@]+)(\:([^/:@]+))?@)?([^/:]{3,})[:/](.+?)(\.git|\/?)$'
 # hg url (no #rev)
 regex_hg_url = r'^(file|ssh|https?)://([^/:]+)/([^/]+)/?([^/]+?)?$'