Strongly bind security objects to connection object

There is already an implicit connection between them, so let's make
it explicit. This allows easy lookup outside of the processMsg() function.
diff --git a/common/rfb/SSecurityVeNCrypt.h b/common/rfb/SSecurityVeNCrypt.h
index f9c753f..06758b8 100644
--- a/common/rfb/SSecurityVeNCrypt.h
+++ b/common/rfb/SSecurityVeNCrypt.h
@@ -36,9 +36,9 @@
 
   class SSecurityVeNCrypt : public SSecurity {
   public:
-    SSecurityVeNCrypt(SecurityServer *sec);
+    SSecurityVeNCrypt(SConnection* sc, SecurityServer *sec);
     ~SSecurityVeNCrypt();
-    virtual bool processMsg(SConnection* sc);// { return true; }
+    virtual bool processMsg();
     virtual int getType() const { return chosenType; }
     virtual const char* getUserName() const;
     virtual SConnection::AccessRights getAccessRights() const;