print fatal UNO exceptions' text in a friendly way from OpenClients failures

desktop/source/app/app.cxx

@@ -2199,6 +2199,7 @@ IMPL_LINK( Desktop, OpenClients_Impl, void*, EMPTYARG )
 {
     RTL_LOGFILE_PRODUCT_CONTEXT( aLog, "PERFORMANCE - DesktopOpenClients_Impl()" );
 
+    try {
         OpenClients();
 
         OfficeIPCThread::SetReady();
@@ -2209,6 +2210,10 @@ IMPL_LINK( Desktop, OpenClients_Impl, void*, EMPTYARG )
 
         if (getenv ("OOO_EXIT_POST_STARTUP"))
             new ExitTimer();
+    } catch (const ::com::sun::star::uno::Exception &e) {
+        String a( RTL_CONSTASCII_USTRINGPARAM( "UNO exception during client open:\n" ) );
+        Application::Abort( a + e.Message );
+    }
     return 0;
 }