Don't convert telegram chat_id

closes #5840

docs/configuration.md

@@ -37,6 +37,15 @@ Using this scheme, all configuration settings will also be available as environm
 
 Please note that Environment variables will overwrite corresponding settings in your configuration, but command line Arguments will always win.
 
+Common example:
+
+```
+FREQTRADE__TELEGRAM__CHAT_ID=<telegramchatid>
+FREQTRADE__TELEGRAM__TOKEN=<telegramToken>
+FREQTRADE__EXCHANGE__KEY=<yourExchangeKey>
+FREQTRADE__EXCHANGE__SECRET=<yourExchangeSecret>
+```
+
 !!! Note
     Environment variables detected are logged at startup - so if you can't find why a value is not what you think it should be based on the configuration, make sure it's not loaded from an environment variable.
 

freqtrade/configuration/environment_vars.py

@@ -32,6 +32,7 @@ def flat_vars_to_nested_dict(env_dict: Dict[str, Any], prefix: str) -> Dict[str,
     :param prefix: Prefix to consider (usually FREQTRADE__)
     :return: Nested dict based on available and relevant variables.
     """
+    no_convert = ['CHAT_ID']
     relevant_vars: Dict[str, Any] = {}
 
     for env_var, val in sorted(env_dict.items()):
@@ -39,9 +40,9 @@ def flat_vars_to_nested_dict(env_dict: Dict[str, Any], prefix: str) -> Dict[str,
             logger.info(f"Loading variable '{env_var}'")
             key = env_var.replace(prefix, '')
             for k in reversed(key.split('__')):
-                val = {k.lower(): get_var_typed(val) if type(val) != dict else val}
+                val = {k.lower(): get_var_typed(val)
+                       if type(val) != dict and k not in no_convert else val}
             relevant_vars = deep_merge_dicts(val, relevant_vars)
-
     return relevant_vars
 
 

tests/test_configuration.py

@@ -1359,6 +1359,7 @@ def test_flat_vars_to_nested_dict(caplog):
         'FREQTRADE__ASK_STRATEGY__PRICE_SIDE': 'bid',
         'FREQTRADE__ASK_STRATEGY__cccc': '500',
         'FREQTRADE__STAKE_AMOUNT': '200.05',
+        'FREQTRADE__TELEGRAM__CHAT_ID': '2151',
         'NOT_RELEVANT': '200.0',  # Will be ignored
     }
     expected = {
@@ -1373,6 +1374,9 @@ def test_flat_vars_to_nested_dict(caplog):
             },
             'some_setting': True,
             'some_false_setting': False,
+        },
+        'telegram': {
+            'chat_id': '2151'
         }
     }
     res = flat_vars_to_nested_dict(test_args, ENV_VAR_PREFIX)