ProjectManager: Avoid connecting a signal more than once.

This solves a crash when loading two project in the same session.

src/Project/ProjectManager.cpp

@@ -87,6 +87,8 @@ ProjectManager::ProjectManager() : m_projectFile( NULL ), m_needSave( false )
     VLMC_CREATE_PROJECT_STRING( "general/VLMCWorkspace", QDir::homePath(), "Workspace location", "The place where all project's videos will be stored" );
 
     VLMC_CREATE_PROJECT_STRING( "general/ProjectName", unNamedProject, "Project name", "The project name" );
+
+    connect( Library::getInstance(), SIGNAL( projectLoaded() ), this, SLOT( loadTimeline() ) );
 }
 
 ProjectManager::~ProjectManager()
@@ -144,7 +146,6 @@ void    ProjectManager::loadProject( const QString& fileName )
 
     QDomElement     root = m_domDocument->documentElement();
 
-    connect( Library::getInstance(), SIGNAL( projectLoaded() ), this, SLOT( loadTimeline() ) );
     Library::getInstance()->loadProject( root );
 }