message: readme: Remove stray line
  No longer needed thanks to
diff: @@ -38,7 +38,6 @@ The only supported installation method at this time is from source. Proper insta
  ```sh
  git clone https://aur.archlinux.org/alacritty-git.git
  cd alacritty-git
  -pacman -S rustup # needed until Rust 1.15 is available (see PR #131)
  makepkg -isr
  ```
  