Improve integrity error, error message.

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncManager.java

@@ -209,8 +209,7 @@ abstract public class SyncManager {
                 syncResult.databaseError = true;
             } else if (e instanceof Exceptions.IntegrityException) {
                 App.log.log(Level.SEVERE, "Integrity error", e);
-                // FIXME: Make a proper error message
-                messageString = R.string.sync_error;
+                messageString = R.string.sync_error_integrity;
                 syncResult.stats.numParseExceptions++;
             } else {
                 App.log.log(Level.SEVERE, "Unknown sync error", e);

app/src/main/res/values/strings.xml

@@ -262,6 +262,7 @@
     <string name="sync_error_contacts">Address book synchronization failed (%s)</string>
     <string name="sync_error_tasks">Task synchronization failed (%s)</string>
     <string name="sync_error">Error while %s</string>
+    <string name="sync_error_integrity">Integrity error while %s</string>
     <string name="sync_error_http_dav">Server error while %s</string>
     <string name="sync_error_local_storage">Database error while %s</string>
     <string-array name="sync_error_phases">