Add short message to indicate why a feed url can't be updated with a FreshRSS account

appcompose/src/main/java/com/readrops/app/compose/feeds/dialogs/UpdateFeedDialog.kt

@@ -64,6 +64,10 @@ fun UpdateFeedDialog(
                     Text(
                         text = state.feedUrlError?.errorText().orEmpty()
                     )
+                } else if (state.isFeedUrlReadOnly) {
+                    Text(
+                        text = stringResource(id = R.string.feed_url_read_only)
+                    )
                 }
             }
         )

appcompose/src/main/res/values-fr/strings.xml

@@ -164,4 +164,5 @@
     <string name="http_error_4XX">Erreur HTTP %1$d, veuillez vérifier vos champs</string>
     <string name="http_error_5XX">Erreur HTTP %1$d, erreur serveur</string>
     <string name="http_error">Erreur HTTP %1$d</string>
+    <string name="feed_url_read_only">L\'API de FreshRSS ne permet pas de modifier l\'URL</string>
 </resources>

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

@@ -170,4 +170,5 @@
     <string name="http_error_4XX">HTTP error %1$d, please check your fields</string>
     <string name="http_error_5XX">HTTP error %1$d, server error</string>
     <string name="http_error">HTTP error %1$d</string>
+    <string name="feed_url_read_only">FreshRSS API doesn\'t support Feed URL modification</string>
 </resources>