string: fix strncoll to trim string lengths

MSVC implementation does not stop on zero terminator.

Signed-off-by: Simon Rozman <simon.rozman@amebis.si>

include/stdex/string.hpp

@@ -1511,7 +1511,7 @@ namespace stdex
 		stdex_assert(str1 || !count1);
 		stdex_assert(str2 || !count2);
 		auto& collate = std::use_facet<std::collate<T>>(locale);
-		return collate.compare(str1, str1 + count1, str2, str2 + count2);
+		return collate.compare(str1, str1 + strnlen(str1, count1), str2, str2 + strnlen(str2, count2));
 	}
 
 	///