Minor fixes.

servermanager.py

@@ -38,7 +38,7 @@ def get_nations():
 
         era_match = re.match(r"-+ Era (\d+) -+", line)
         if era_match:
-            current_era = f"Era {era_match.group(1)}"
+            current_era = f"{era_match.group(1)}"
             nations[current_era] = {}
             continue
 
@@ -151,7 +151,7 @@ def server_command_builder(
     if team_game:
         for team in teams:
             # TODO Can team have more than one disciple and pretender?
-            if team[0] not in available_nations[era]:
+            if team[0] not in available_nations[str(era)]:
                 return "ERROR_INVALID_NATION"
 
             command.append(
@@ -221,9 +221,9 @@ def server_command_builder(
         command.append(" --vwrap")
     if not hwrap:
         command.append(" --nohwrap")
-    if not ai_slots == []:
+    if ai_slots:
         for ai in ai_slots:
-            if ai[0] not in available_nations[era]:
+            if ai[0] not in available_nations[str(era)]:
                 return "ERROR_INVALID_NATION"
             match ai[1]:
                 case 1:
@@ -237,9 +237,9 @@ def server_command_builder(
                 case 5:
                     command.append(" --masterai " + str(ai[0]))
                 case 6:
-                    command.append(" --impai" + str(ai[0]))
+                    command.append(" --impai " + str(ai[0]))
                 case _:
-                    return "EROR_INVALID_AI"
+                    return "ERROR_INVALID_AI"
 
     return "".join(command)