Fix console warnings about undefined variables

JS ERROR: !!!   WARNING: 'assignment to undeclared variable col'
JS ERROR: !!!   WARNING: file 'drop-down-terminal@gs-extensions.zzrough.org/terminal.js' line 63 exception 0 number 156
JS ERROR: !!!   WARNING: 'assignment to undeclared variable terminal'
JS ERROR: !!!   WARNING: file 'drop-down-terminal@gs-extensions.zzrough.org/terminal.js' line 533 exception 0 number 156