[shell] Add backspace character in ReadLine

Signed-off-by: Andrei Menzopol <[email protected]>

src/lib/shell/MainLoopDefault.cpp

@@ -69,6 +69,7 @@ size_t ReadLine(char * buffer, size_t max)
                 done = true;
             }
             break;
+        case 0x08:
         case 0x7F:
             // Do not accept backspace character (i.e. don't increment line_sz) and remove 1 additional character if it exists.
             if (line_sz >= 1u)