Also clears ESC_START on interrupt characters during sequences.

Otherwise, the rest of the input is interpreted as a new escape
sequence.
For the ESC character, ESC_START is re-set in tcontrolcode.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea and freedom
500 Internal Server Error

Gitea Version: 1.28.0+dev-505-g31b4d79a84