Removing f-string from orthancDatabaseBrowser for python3.5 compatibility

orthancDatabaseBrowser.py

@@ -100,7 +100,8 @@ class orthancDB:
 
     def changes(self,limit=10,since=0):
       url=self.net.getCoreURL()
-      url+=f'/changes?limit={limit}&since={since}'
+      #url+=f'/changes?limit={limit}&since={since}'
+      url+='/changes?limit={}&since={}'.format(limit,since)
       response=self.net.get(url)
       return extractJSON(response.data)