Fix is_palindrome_recursive logic in strings/palindrome.py (#12946)

* Fix: is_palindrome_recursive logic for 2-char strings

* Update palindrome.py

* Update palindrome.py

* Update palindrome.py

---------

Co-authored-by: Maxim Smolskiy <mithridatus@mail.ru>

strings/palindrome.py

@@ -11,6 +11,8 @@ test_data = {
     "BB": True,
     "ABC": False,
     "amanaplanacanalpanama": True,  # "a man a plan a canal panama"
+    "abcdba": False,
+    "AB": False,
 }
 # Ensure our test data is valid
 assert all((key == key[::-1]) is value for key, value in test_data.items())
@@ -61,7 +63,7 @@ def is_palindrome_recursive(s: str) -> bool:
     >>> all(is_palindrome_recursive(key) is value for key, value in test_data.items())
     True
     """
-    if len(s) <= 2:
+    if len(s) <= 1:
         return True
     if s[0] == s[len(s) - 1]:
         return is_palindrome_recursive(s[1:-1])