Fixed #20968 -- Checked Spatialite metadata before migrations

Thanks Kenial S. Lee for the initial patch.

django/contrib/gis/db/backends/spatialite/creation.py

@@ -30,11 +30,3 @@ class SpatiaLiteCreation(DatabaseCreation):
                               style.SQL_FIELD(gqn(f.column)) + ');')
 
         return output
-
-    def _create_test_db_pre_migrate_sql(self):
-        """
-        Creates the spatial metadata tables.
-        """
-        cur = self.connection._cursor()
-        arg = "1" if self.connection.features.supports_initspatialmetadata_in_one_transaction else ""
-        cur.execute("SELECT InitSpatialMetaData(%s)" % arg)