Remove slow migration and add fix to sanitize errors

Getting rid of the slow migration and preventing the Error to occur

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19608

Added 1 commit:

• 99f7b6d2 - spec and fix for sanitize method

Not adding a CHANGELOG entry as the original fix is still relevant - Set import_url validation to be more strict

@rymai feel free to have a look. I would say we definitely want this in the next RC

Reassigned to @rymai

mentioned in merge request !5149 (merged)

Thanks James!

Status changed to merged

mentioned in commit 11ba19e3

@rymai actually, should this be Pick into Stable ? :/

@jameslopez No, I'm still merging master into stable for one more week! ;)

ahhh okay! thanks Remy!

Removed ~149423 label