Show unsupported locale for parsing warning only when when enabling address parsing

1- Go to Administer >> Localization >> Languages, Currency, Locations.
2- Change the default Language to anything other than "English (United States)", "English (Canada)" or "French (Canada)", for example change it to "English (United Kingdom)" and save the settings.
3- Go Administer >> Localization >> Address Settings.
4- At "Address Editing" section, check "Street Address Parsing" option and hit save.
5- Now any time you try to edit a contact with street address, a warning says "Unsupported locale specified to parseStreetAddress en_GB, Proceeding with en_US locale." will appear.

But this is not ideal for users, the warning should not appear each time you try to edit a user and it should default to en_US silently if the locale is not supported, the warning above should only appear when the admin enable "Street Address Parsing" (step 4 above) in case the default locale is not supported.