Connect to custom board STM32L053 - STLINK-V2 - SWD
Maybe it was valid before but the connect_assert_srst has been added to reconnect under reset.
So, can you try putting back the original line 71 and give the openocd log (with the -d arg) if it is not working.
Do you connect the reset line to the STM32L476 ?
Rgds,
Laurent