[2232] Fix Missing Preferences

Fixes an issue that could present on clean installs where the EDSM keys weren't generated properly.

When the heck did this bug get introduced???

plugins/edsm.py

@@ -491,6 +491,20 @@ def credentials(cmdr: str) -> tuple[str, str] | None:
     edsm_usernames = config.get_list('edsm_usernames')
     edsm_apikeys = config.get_list('edsm_apikeys')
 
+    if not edsm_usernames:  # https://github.com/EDCD/EDMarketConnector/issues/2232
+        edsm_usernames = ["" for _ in range(len(cmdrs))]
+        config.set('edsm_usernames', edsm_usernames)
+    else:  # Check for Mismatched Length - fill with null values.
+        if len(edsm_usernames) < len(cmdrs):
+            edsm_usernames.extend(["" for _ in range(len(cmdrs) - len(edsm_usernames))])
+
+    if not edsm_apikeys:
+        edsm_apikeys = ["" for _ in range(len(cmdrs))]
+        config.set('edsm_apikeys', edsm_apikeys)
+    else:  # Check for Mismatched Length - fill with null values.
+        if len(edsm_apikeys) < len(cmdrs):
+            edsm_apikeys.extend(["" for _ in range(len(cmdrs) - len(edsm_apikeys))])
+
     if cmdr in cmdrs and len(cmdrs) == len(edsm_usernames) == len(edsm_apikeys):
         idx = cmdrs.index(cmdr)
         if idx < len(edsm_usernames) and idx < len(edsm_apikeys):