use a dropdown for callsign database setting; add aprs.fi

owrx/controllers/settings/general.py

@@ -168,12 +168,17 @@ class GeneralSettingsController(SettingsFormController):
                     infotext="Specifies how log markers / grids will remain visible on the map",
                     append="s",
                 ),
-                TextInput(
-                    "callsign_url",
-                    "Callsign database URL",
-                    infotext="Specifies callsign lookup URL, such as QRZ.COM "
-                    + "or QRZCQ.COM. Place curly brackers ({}) where callsign "
-                    + "is supposed to be.",
+                DropdownInput(
+                    "callsign_service",
+                    "Callsign database service",
+                    infotext="Allows users to navigate to an external callsign database service by clicking on "
+                    + "callsigns",
+                    options=[
+                        Option(None, "disabled"),
+                        Option("qrzcq", "qrzcq.com"),
+                        Option("qrz", "qrz.com"),
+                        Option("aprsfi", "aprs.fi"),
+                    ],
                 ),
             ),
         ]