Fix UI reset after MGMT_PROTOS change in 0.20.6

In 0.20.6 TELNET_OBJS_LISTSRC, SSH_OBJS_LISTSRC, and RDP_OBJS_LISTSRC
were replaced with a single MGMT_PROTOS option, but the UI reset code
was not updated and so still attempted to reset the objects which no
longer existed...