fix: rename parameter to avoid -Wshadow warning in message_t constructor

The 'data' parameter in the deprecated array constructor shadows
message_t::data(), triggering -Wshadow warnings on GCC. Rename
to 'arr' to resolve.

Fixes #641

Author: Charlie Tonneslan

zmq.hpp

@@ -483,8 +483,8 @@ class message_t
       typename = typename std::enable_if<detail::is_char_type<Char>::value>::type>
     ZMQ_DEPRECATED("from 4.7.0, use constructors taking iterators, (pointer, size) "
                    "or strings instead")
-    explicit message_t(const Char (&data)[N]) :
-        message_t(detail::ranges::begin(data), detail::ranges::end(data))
+    explicit message_t(const Char (&arr)[N]) :
+        message_t(detail::ranges::begin(arr), detail::ranges::end(arr))
     {
     }