Add sso db field

SSO field tracks whether the user wants to enable SSO integration
or not.

migrations/schema.sql

@@ -68,6 +68,7 @@ CREATE TABLE IF NOT EXISTS apps(
     memoryLimit BIGINT DEFAULT 0,
     altDomain VARCHAR(256),
     xFrameOptions VARCHAR(512),
+    sso BOOLEAN DEFAULT 1, // whether user chose to enable SSO
 
     lastBackupId VARCHAR(128), // tracks last valid backup, can be removed