liquid_feedback_frontend: env/util/trim.lua annotate

liquid_feedback_frontend

Silence compiler warnings regarding discarded const qualifier in mldap library

rev	line source
bsw/jbe@6	1 function util.trim(string)
mail@236	2 if string == nil then
mail@236	3 return string
mail@236	4 end
bsw@9	5 return (string:gsub("^%s", ""):gsub("%s$", ""):gsub("%s+", " "))
mail@236	6 end