respect :compiler!

otherwise :compiler does not respect global settings;
setting &l:makeprg is fine though, see discussion at vim/vim#18686

Author: Konfekt

compiler/golint.vim

@@ -11,6 +11,7 @@ let &l:makeprg = 'staticcheck ./...'
 if len(get(g:, 'gopher_build_tags', [])) > 0
   let &l:makeprg .= printf(' --build-tags "%s"', join(gopher#bufsetting('gopher_build_tags', []) ' '))
 endif
+exe 'CompilerSet makeprg='..escape(&l:makeprg, ' \|"')
 
 " golangci-lint:
 "   benchmark_test.go:34:2   deadcode  `valFormT2` is unused