Skip Welcome screen when there's only one connection and it's loaded

If the connection is stuck, we can still log in to a different one that way.

(cherry picked from commit 7150445f8e)

src/qml/WelcomePage.qml

@@ -110,6 +110,12 @@ FormCard.FormCardPage {
                     }
                 }
             }
+            onCountChanged: {
+                if (loadingAccounts.count === 0 && loadedAccounts.count === 1 && showExisting) {
+                    Controller.activeConnection = AccountRegistry.data(AccountRegistry.index(0, 0), 257);
+                    root.connectionChosen();
+                }
+            }
         }
     }