main/asterisk: security upgrade to 12.7.1

AST-2014-012: Unauthorized access in the presence of ACLs with mixed IP
              address families
AST-2014-018: Permission Escalation through DB dialplan function
AST-2014-017: Permission Escalation via ConfBridge dialplan function and
              AMI ConfbridgeStartRecord Action
AST-2014-013: Unauthorized access in the presence of ACLs in the PJSIP stack
AST-2014-015: Remote crash vulnerability in PJSIP channel driver
AST-2014-016: Remote crash vulnerability in PJSIP channel driver