Reverting 'Two-factor authentication' support as it cause OSX and docker build failures.

This reverts commit 787a441343.

web/migrations/versions/15c88f765bc8_.py

@@ -1,44 +0,0 @@
-##########################################################################
-#
-# pgAdmin 4 - PostgreSQL Tools
-#
-# Copyright (C) 2013 - 2021, The pgAdmin Development Team
-# This software is released under the PostgreSQL Licence
-#
-##########################################################################
-
-"""Update DB to version 14
-
-Added a table `user_mfa` for saving the options on MFA for different sources.
-
-Revision ID: 15c88f765bc8
-Revises: 6650c52670c2
-Create Date: 2021-06-22 17:33:12.533825
-
-"""
-from pgadmin.model import db
-
-
-# revision identifiers, used by Alembic.
-revision = '15c88f765bc8'
-down_revision = '6650c52670c2'
-branch_labels = None
-depends_on = None
-
-
-def upgrade():
-    db.engine.execute("""
-CREATE TABLE user_mfa(
-    user_id  INTEGER NOT NULL,
-    mfa_auth VARCHAR(256) NOT NULL,
-    options  TEXT,
-    PRIMARY KEY (user_id, mfa_auth),
-    FOREIGN KEY(user_id) REFERENCES user (id)
-)
-    """)
-    # ### end Alembic commands ###
-
-
-def downgrade():
-    # pgAdmin only upgrades, downgrade not implemented.
-    pass