Change error message

Author: mgreter

src/fn_miscs.cpp

@@ -213,7 +213,7 @@ namespace Sass {
     {
       String_Constant* ss = Cast<String_Constant>(env["$name"]);
       if (!ss) {
-        error("$name: " + (env["$name"]->to_string()) + " is not a string for `get-function'", pstate, traces);
+        error("$name: " + (env["$name"]->to_string()) + " is not a string.", pstate, traces);
       }
 
       std::string name = unquote(ss->value());

src/fn_utils.hpp

@@ -41,7 +41,7 @@ namespace Sass {
     {
       T* val = Cast<T>(env[argname]);
       if (!val) {
-        error("argument `" + argname + "` of `" + sig + "` must be a " + T::type_name(), pstate, traces);
+        error(argname + " is not a " + T::type_name(), pstate, traces);
       }
       return val;
     }