[WINLOGON] On logoff, also disconnect from any remote location

This avoids keeping connections open and reopening them as soon
as the user reopens their session.
This fixes network shared being duplicated each time session
is reopened.

CORE-15012

base/system/winlogon/sas.c

@@ -657,6 +657,9 @@ LogoffShutdownThread(
         ret = 0;
     }
 
+    /* Cancel all the user connections */
+    WNetClearConnections(0);
+
     if (LSData->Session->UserToken)
         RevertToSelf();