MM-34080: Removing sqlite entirely (#17188)

* MM-34080: Removing sqlite entirely

The initial commit missed removing this blank import.
So the library still remained in our vendor directory.
Removing it for good now.

Bye bye sqlite.

https://mattermost.atlassian.net/browse/MM-34080

* fix go.mod

go.mod

@@ -76,7 +76,6 @@ require (
 	github.com/mattermost/ldap v0.0.0-20201202150706-ee0e6284187d
 	github.com/mattermost/logr v1.0.13
 	github.com/mattermost/rsc v0.0.0-20160330161541-bbaefb05eaa0
-	github.com/mattn/go-sqlite3 v2.0.3+incompatible
 	github.com/mholt/archiver/v3 v3.5.0
 	github.com/miekg/dns v1.1.39 // indirect
 	github.com/minio/md5-simd v1.1.2 // indirect