Dealing with successors in interest.

In the case of any investment made by a savings bank in a real estate loan, in the event the ownership of the real estate security or any part thereof becomes vested in a person other than the party or parties originally executing the security instruments, and provided there is not an agreement in writing to the contrary, a savings bank may, without notice to such party or parties, deal with such successor or successors in interest with reference to said mortgage and the debt thereby secured in the same manner as with such party or parties, and may forbear to sue or may extend time for payment of or otherwise modify the terms of the debt secured thereby, without discharging or in any way affecting the original liability of such party or parties thereunder or upon the debt thereby secured.