Fix data limit fallback and narrow traffic parsing exceptions

Agent-Logs-Url: https://github.com/kr0sh512/tt-simple/sessions/34c3052e-7b55-4cb8-9fee-0ee1ba315691

Co-authored-by: kr0sh512 <46405586+kr0sh512@users.noreply.github.com>

bot.py

@@ -4,7 +4,7 @@ import logging
 import os
 from dataclasses import dataclass
 from datetime import datetime, timezone
-from decimal import Decimal, ROUND_HALF_UP
+from decimal import Decimal, ROUND_HALF_UP, InvalidOperation
 from typing import Any
 
 import aiohttp
@@ -399,7 +399,7 @@ class VpnBot:
             action = "extended"
 
         expire_at = add_months(expire_from, months)
-        data_limit = int(current.get("data_limit") or 50 * GB) if current else 50 * GB
+        data_limit = int(current.get("data_limit", 50 * GB)) if current else 50 * GB
         data_limit_reset_strategy = (
             current.get("data_limit_reset_strategy") or "month"
         ) if current else "month"
@@ -552,7 +552,7 @@ class VpnBot:
             return
         try:
             gb_value = Decimal(arg)
-        except Exception:
+        except (ValueError, InvalidOperation):
             await message.answer("Invalid value. Example: /set_traffic 75")
             return
         if gb_value <= 0: