Java doesn't support negative NaN but redis does seem to

Signed-off-by: Paulo Lopes <pmlopes@gmail.com>

Author: pmlopes

src/main/java/io/vertx/redis/client/impl/ReadableBuffer.java

@@ -117,6 +117,8 @@ Number readNumber(int end, NumericType type) {
               number = Double.NaN;
           } else if (bytes.length == 4 && bytes[0] == '-' && bytes[1] == 'i' && bytes[2] == 'n' && bytes[3] == 'f') {
             number = Double.NEGATIVE_INFINITY;
+          } else if (bytes.length == 4 && bytes[0] == '-' && bytes[1] == 'n' && bytes[2] == 'a' && bytes[3] == 'n') {
+            number = Double.NaN;
           } else {
             number = Double.parseDouble(new String(bytes, StandardCharsets.US_ASCII));
           }