Buffer overflow read in keyboard.cpp

[drfiemost]

Detected with ASan at exit after pressing ESC:

 ../src/keyboard.cpp:119:19: runtime error: load of address 0x7f6c0c1e9360 with insufficient space for an object of type 'char'
0x7f6c0c1e9360: note: pointer points here
 00 00 00 00  1b 1b 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  26 dd ff 0b
              ^ 
../src/keyboard.cpp:146:18: runtime error: load of address 0x7f6c0c1e9361 with insufficient space for an object of type 'char'
0x7f6c0c1e9361: note: pointer points here
 00 00 00  1b 1b 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  26 dd ff 0b 6c
              ^