Only variables should be passed by reference in uuid_views_data() (in uuid.views.inc)

The php function array_shift() is defined as follows:

mixed function array_shift(&$array);

Which means the parameter the function is designed to accept is a variable (accepted by reference), and should not be any direct value.

However, in this line, we are sending an array as a value rather than a variable to the function:

    $field = array_shift(array_keys($schema['fields']));

While this will still work, we should change the code to pass what PHP is designed to accept: a variable.

    $field_keys = array_keys($schema['fields']);
    $field = array_shift($field_keys);

I'll be including a patch to make this change. This should also silence any E_STRICT errors users are getting.