Fix regex to properly cut default value for default empty string and default whitespace
User Case Description
I've faced extra "ALTER TABLE..." requests on every app start with Gorm auto-migrate. Investigated that Gorm doesn't cut properly "default" value, if it is empty string or whitespace. Returned to case with 2 separate regexes that was first added in https://github.com/go-gorm/postgres/pull/143#discussion_r1056736772
What did this pull request do?
Fix regex to properly cut default value for default empty string and default whitespace
User Case Description
I've faced extra "ALTER TABLE..." requests on every app start with Gorm auto-migrate. Investigated that Gorm doesn't cut properly "default" value, if it is empty string or whitespace. Returned to case with 2 separate regexes that was first added in https://github.com/go-gorm/postgres/pull/143#discussion_r1056736772