gcc 4.9.3 warnings.

[Techwolf]

When building the libqtelegram-ae, I got the following warnings:

x86_64-pc-linux-gnu-g++ -c -march=native -O2 -pipe -ggdb -Wall -W -D_REENTRANT -fPIC -DLIBQTELEGRAM_LIBRARY -DLQTG_DISABLE_LOG -DQT_NO_DEBUG -DQT_MULTIMEDIA_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I. -isystem /usr/include -I/usr/local/include/ -isystem /usr/include/qt5 -isystem /usr/include/qt5/QtMultimedia -isystem /usr/include/qt5/QtGui -isystem /usr/include/qt5/QtNetwork -isystem /usr/include/qt5/QtCore -I. -I/usr/lib64/qt5/mkspecs/linux-g++ -o session.o core/session.cpp
util/cryptoutils.cpp: In member function ‘qint32 CryptoUtils::computeKeyFingerprint(const QByteArray&, const QByteArray&)’:
util/cryptoutils.cpp:329:38: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     qint32 keyFingerprint = (*(int *)md5) ^ (*(int *)(md5 + 4));
                                      ^

x86_64-pc-linux-gnu-g++ -c -march=native -O2 -pipe -ggdb -Wall -W -D_REENTRANT -fPIC -DLIBQTELEGRAM_LIBRARY -DLQTG_DISABLE_LOG -DQT_NO_DEBUG -DQT_MULTIMEDIA_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I. -isystem /usr/include -I/usr/local/include/ -isystem /usr/include/qt5 -isystem /usr/include/qt5/QtMultimedia -isystem /usr/include/qt5/QtGui -isystem /usr/include/qt5/QtNetwork -isystem /usr/include/qt5/QtCore -I. -I/usr/lib64/qt5/mkspecs/linux-g++ -o session.o core/session.cpp
core/session.cpp: In member function ‘qint32 Session::aesEncryptMessage(Session::EncryptedMsg*)’:
core/session.cpp:419:91: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     qCDebug(TG_CORE_SESSION) << "sending message with sha1" << QString::number(*(qint32 *)sha1Buffer, 8);
                                                                                           ^

x86_64-pc-linux-gnu-g++ -c -march=native -O2 -pipe -ggdb -Wall -W -D_REENTRANT -fPIC -DLIBQTELEGRAM_LIBRARY -DLQTG_DISABLE_LOG -DQT_NO_DEBUG -DQT_MULTIMEDIA_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -I. -isystem /usr/include -I/usr/local/include/ -isystem /usr/include/qt5 -isystem /usr/include/qt5/QtMultimedia -isystem /usr/include/qt5/QtGui -isystem /usr/include/qt5/QtNetwork -isystem /usr/include/qt5/QtCore -I. -I/usr/lib64/qt5/mkspecs/linux-g++ -o dcauth.o core/dcauth.cpp
core/dcauth.cpp: In member function ‘void DCAuth::processAuthComplete(InboundPkt&)’:
core/dcauth.cpp:309:36: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     m_dc->setServerSalt(*(qint64 *)m_serverNonce ^ *(qint64 *)m_newNonce);
                                    ^
core/dcauth.cpp:309:63: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     m_dc->setServerSalt(*(qint64 *)m_serverNonce ^ *(qint64 *)m_newNonce);
                                                               ^

Experience has taught me that warnings later turn into errors when things get upgraded.