🚨 fix a warning

include/nlohmann/detail/input/lexer.hpp

@@ -936,7 +936,7 @@ class lexer : public lexer_base<BasicJsonType>
 
         while (*p >= '0' and * p <= '9')
         {
-            val = (10 * val) + (*p - '0');
+            val = (10U * val) + static_cast<number_unsigned_t>((*p - '0'));
             p++;
         }