Fix segfault
Fix segfault

Fix segfault when passing nil value to contains function

haka-security/haka,nabilbendafi/haka,Wingless-Archangel/haka,nabilbendafi/haka,lcheylus/haka,lcheylus/haka,lcheylus/haka,LubyRuffy/haka,haka-security/haka,Wingless-Archangel/haka,LubyRuffy/haka,haka-security/haka,nabilbendafi/haka