Fixed issue with ICEAuthority ownership stealing when programs were

run using tdesu in a user session. This resolves issue TDE/tde#77.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit 8ce8530d92)

tdesu/process.cpp

@@ -359,6 +359,7 @@ int PtyProcess::exec(const TQCString &command, const QCStringList &args)
         putenv(const_cast<TQCString&>(*it).data());
     }
     unsetenv("TDE_FULL_SESSION");
+    unsetenv("XDG_RUNTIME_DIR");
     
     // set temporarily LC_ALL to C, for su (to be able to parse "Password:")
     const char* old_lc_all = getenv( "LC_ALL" );