Fix brace initialization for std::array in serialization unit tests

Signed-off-by: rusloker <klokotkov@ya.ru>

Author: RUSLoker

tests/src/unit-serialization.cpp

@@ -311,14 +311,14 @@ TEST_CASE("dump for basic_json with long double number_float_t")
     SECTION("round-trip dump/parse")
     {
         constexpr std::array<long double, 13> values =
-        {
+        {{
             0.0L, -0.0L, 1.0L, -1.0L,
             0.5L, -0.5L, 1.5L, -2.25L,
             1.23e45L, 1.23e-45L,
             (std::numeric_limits<long double>::min)(),
             std::numeric_limits<long double>::lowest(),
             (std::numeric_limits<long double>::max)()
-        };
+        }};
 
         for (long double v : values)
         {