/W4: Fix incorrect type cast

Values passed to functions from '<cctype>' must be representable as unsigned chars to avoid undefined behavior.

r5dev/public/utility/utility.cpp

@@ -244,7 +244,7 @@ char* StripQuotes(const char* pInBuffer, char* pOutBuffer, int nOutBufferSize)
 bool HasPartial(const string& svInput, const string& svPartial)
 {
     auto it = std::search(svInput.begin(), svInput.end(),
-        svPartial.begin(), svPartial.end(), [](char ci, char cp)
+        svPartial.begin(), svPartial.end(), [](unsigned char ci, unsigned char cp)
         {
             return std::toupper(ci) == std::toupper(cp);
         }