Fix compile error.

Author: h2zero

src/NimBLEAddress.cpp

@@ -169,7 +169,7 @@ bool NimBLEAddress::operator !=(const NimBLEAddress & rhs) const {
  * that accept std::string and/or or it's methods as a parameter.
  */
 NimBLEAddress::operator std::string() const {
-    char buffer[26];
+    char buffer[28];
     snprintf(buffer, sizeof(buffer), "%02x:%02x:%02x:%02x:%02x:%02x type: %d",
                                      m_address[5], m_address[4], m_address[3],
                                      m_address[2], m_address[1], m_address[0],