Docs: Correct param documentation for WP_Term_Query.

The description of `$meta_type` introduced in [40053] was incorrect.

Props dlh.
Merges [43559] to the 4.9 branch.
Fixes #44608.

git-svn-id: https://develop.svn.wordpress.org/branches/4.9@43621 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/class-wp-term-query.php

@@ -172,8 +172,8 @@ class WP_Term_Query {
 	 *                                                Can be used in conjunction with `$meta_value`. Default empty.
 	 *     @type string       $meta_value             Limit terms to those matching a specific metadata value.
 	 *                                                Usually used in conjunction with `$meta_key`. Default empty.
-	 *     @type string       $meta_type              Type of object metadata is for (e.g., comment, post, term, or user).
-	 *                                                Default empty.
+	 *     @type string       $meta_type              MySQL data type that the `$meta_value` will be CAST to for
+	 *                                                comparisons. Default empty.
 	 *     @type string       $meta_compare           Comparison operator to test the 'meta_value'. Default empty.
 	 * }
 	 */