Fix account_from_hex_string + refactoring

Author: philogicae

src/aleph/sdk/account.py

@@ -54,12 +54,11 @@ def account_from_hex_string(
         private_key_str = private_key_str[2:]
 
     if not chain:
-        if not account_type:
-            account_type = load_chain_account_type(Chain.ETH)  # type: ignore
-        return account_type(bytes.fromhex(private_key_str))  # type: ignore
+        chain = settings.DEFAULT_CHAIN
+    if not account_type:
+        account_type = load_chain_account_type(chain)
+    account = account_type(bytes.fromhex(private_key_str))
 
-    account_type = load_chain_account_type(chain)
-    account = account_type(bytes.fromhex(private_key_str), chain)
     if chain in get_chains_with_super_token():
         account.switch_chain(chain)
     return account  # type: ignore
@@ -73,12 +72,11 @@ def account_from_file(
     private_key = private_key_path.read_bytes()
 
     if not chain:
-        if not account_type:
-            account_type = load_chain_account_type(Chain.ETH)  # type: ignore
-        return account_type(private_key)  # type: ignore
-
-    account_type = load_chain_account_type(chain)
+        chain = settings.DEFAULT_CHAIN
+    if not account_type:
+        account_type = load_chain_account_type(chain)
     account = account_type(private_key)
+
     if chain in get_chains_with_super_token():
         account.switch_chain(chain)
     return account