message: Allow key_binding have space
diff: @@ -256,7 +256,7 @@ impl de::Deserialize for ModsWrapper {
  use ::glutin::{mods, Mods};
  let mut res = Mods::empty();
  for modifier in value.split('|') {
  - match modifier {
  + match modifier.trim() {
  "Command" | "Super" => res |= mods::SUPER,
  "Shift" => res |= mods::SHIFT,
  "Alt" | "Option" => res |= mods::ALT,
  @@ -330,7 +330,7 @@ impl de::Deserialize for ModeWrapper {
  };
  for modifier in value.split('|') {
  - match modifier {
  + match modifier.trim() {
  "AppCursor" => res.mode |= mode::APP_CURSOR,
  "~AppCursor" => res.not_mode |= mode::APP_CURSOR,
  "AppKeypad" => res.mode |= mode::APP_KEYPAD,
  