Minor fixup

Author: jk-jeon

subproject/simple/simple_dragonbox.h

@@ -1233,8 +1233,8 @@ namespace simple_dragonbox {
         template <class T, unsigned Size>
         static constexpr bool valid_float = std::numeric_limits<T>::is_iec559 &&
                                             std::numeric_limits<T>::radix == 2 && sizeof(T) == Size;
-        static_assert(valid_float<float, 4>, "simple_dragonbox: float may not be IEEE 754 binary32");
-        static_assert(valid_float<double, 8>, "simple_dragonbox: double may not be IEEE 754 binary64");
+        static_assert(valid_float<float, 4>, "simple_dragonbox: float may not be IEEE-754 binary32");
+        static_assert(valid_float<double, 8>, "simple_dragonbox: double may not be IEEE-754 binary64");
 
         constexpr void reverse(char* begin, char* end) {
             while (begin < --end) {