Incorrect EOF test in getMessages

[mzygmuntowicz]

In ClientImpl::getMessages there is an icorrect EOF test:
if ($read === false || feof($this->_socket)) {
the correct one should look like:
if ($read === false || (strlen($read) == 0 && @Feof($this->_socket))) {

I found this one having occassional read exceptions during a logoff command. The problem
somehow relates to the fact, that fread can return data, but later feof test signals end of file condition.
Therefore feof should be tested only if fread returns an empty string, which means there is no data, an end of file has been reached or some other error occured.