Also set check date if the generic check date has been set (fixes #5729)

app/src/main/java/de/westnordost/streetcomplete/osm/ResurveyUtils.kt

@@ -45,9 +45,10 @@ fun Tags.updateWithCheckDate(key: String, value: String) {
     set(key, value)
     /* if the value is changed, set the check date only if it has been set before. Behavior
      * before v32.0 was to delete the check date. However, this destroys data that was
-     * previously collected by another surveyor - we don't want to destroy other people's data
+     * previously collected by another surveyor - we don't want to destroy other people's data.
+     * Also, to avoid ambiguities, we should also update (existence) check date.
      */
-    if (previousValue == value || hasCheckDateForKey(key)) {
+    if (previousValue == value || hasCheckDateForKey(key) || hasCheckDate()) {
         updateCheckDateForKey(key)
     }
 }