settings etherpad exturl fix

fet2020/fet2020/settings.py

@@ -12,7 +12,7 @@ env = environ.Env(
     MYSQL_PASSWORD=(str),
     HOST_NAME=(str, "localhost"),
     ETHERPAD_PORT=(str, "9001"),
-    ETHERPAD_HOST=(str, "etherpad2.2020.fet.at"),
+    ETHERPAD_HOST=(str, ""),
 )
 
 # Prints and logs are written to console
@@ -217,12 +217,16 @@ THUMBNAIL_ALIASES = {
         "portrait": {"size": (200, 300), "crop": False},
     },
 }
+ETHERPAD_HOST = env("ETHERPAD_HOST").strip()
+if not ETHERPAD_HOST or ETHERPAD_HOST=="":
+    ETHERPAD_HOST = urljoin("https://" + env("HOST_NAME"), "etherpad/")
+
     
 # ETHERPAD CLIENT
 if DEBUG:
     ETHERPAD_CLIENT = {
         "url": "http://etherpad:" + env("ETHERPAD_PORT"),
-        "exturl": env("ETHERPAD_HOST"),
+        "exturl": ETHERPAD_HOST,
         "apikey": "/srv/etherpad/APIKEY.txt",
     }
 else: