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/SecurityClient.h b/common/rfb/SecurityClient.h
index b8ad831..3074a87 100644
--- a/common/rfb/SecurityClient.h
+++ b/common/rfb/SecurityClient.h
@@ -33,7 +33,7 @@
     SecurityClient(void) : Security(secTypes) {}
 
     /* Create client side CSecurity class instance */
-    CSecurity* GetCSecurity(rdr::U32 secType);
+    CSecurity* GetCSecurity(CConnection* cc, rdr::U32 secType);
 
     static void setDefaults(void);