Fix typos in documentation and comments
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 09c9b21..143abd0 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -2052,7 +2052,7 @@
 /* Checks whether element is contained in container and return 1/0
    accordingly.
 
-   element has to coerce to an one element Unicode string. -1 is
+   element has to coerce to a one element Unicode string. -1 is
    returned in case of an error. */
 
 PyAPI_FUNC(int) PyUnicode_Contains(