Remove plugin check

This exists check ensures that if the plugin has already loaded it won't
load again. This might be useful for plugins that shouldn't be loaded
more than once, but with a colorscheme, it means that we can't switch
to another colorscheme and come back to vim-monokai-tasty.

Obviously we want to be able to load the colorscheme anytime even if it
was loaded previously.

colors/vim-monokai-tasty.vim

@@ -2,9 +2,6 @@
 "
 " Author: Patrick Stockwell <mail@deciphr.net>
 "
-if exists('g:loaded_vim_monokai_tasty')
-  finish
-endif
 
 hi clear
 if exists('syntax_on')
@@ -632,5 +629,3 @@ hi link LspDiagnosticsUnderlineHint DiagnosticUnderlineHint
 " Must be at the end, because of ctermbg=234 bug.
 " https://groups.google.com/forum/#!msg/vim_dev/afPqwAFNdrU/nqh6tOM87QUJ
 set background=dark
-
-let g:loaded_vim_monokai_tasty = 1