Use 0/1 instead of v:true/v:false for compatibility with older vim

versions.

Author: caojoshua

plugin/gitgutter.vim

@@ -118,8 +118,8 @@ command! -bar GitGutterBufferDisable call gitgutter#buffer_disable()
 command! -bar GitGutterBufferEnable  call gitgutter#buffer_enable()
 command! -bar GitGutterBufferToggle  call gitgutter#buffer_toggle()
 
-command! -bar GitGutterQuickFix call gitgutter#quickfix(v:false)
-command! -bar GitGutterQuickFixCurrentFile call gitgutter#quickfix(v:true)
+command! -bar GitGutterQuickFix call gitgutter#quickfix(0)
+command! -bar GitGutterQuickFixCurrentFile call gitgutter#quickfix(1)
 
 " }}}