use the decoded url for launcherPosition

Summary:
launchersOrder and the actual url data can be different:
in case of preferred:/ urls launcherorder will have that for
(for serialization) and the actual appdata url will be decoded as for
instance Applications:firefox.desktop.
this url is the one that needs to be compared to know the actual
launcher order

BUG:418483

Test Plan: firefox stays in first position when pinned as preferred://browser

Reviewers: #plasma, ngraham

Reviewed By: ngraham

Subscribers: ngraham, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D28632

libtaskmanager/launchertasksmodel.cpp

@@ -544,7 +544,7 @@ QStringList LauncherTasksModel::launcherActivities(const QUrl &_url) const
 int LauncherTasksModel::launcherPosition(const QUrl &url) const
 {
     for (int i = 0; i < d->launchersOrder.count(); ++i) {
-        if (launcherUrlsMatch(url, d->launchersOrder.at(i), IgnoreQueryItems)) {
+        if (launcherUrlsMatch(url, d->appData(d->launchersOrder.at(i)).url, IgnoreQueryItems)) {
             return i;
         }
     }