Avoid PHP warning on invalid input

[dd32]

I don't know why, but WordPress.org is getting a bunch of requests similar to this:

/support/search/the/?action[]=bbp-search-request&bbp_search=the

that triggers a PHP warning such as:

E_WARNING: wp-includes/formatting.php:2151 - strtolower() expects parameter 1 to be string, array given

that can be traced back to bbPress passing the action array to sanitize_key.

Attached patch just disregards the parameter if it's not a string.

[johnjamesjacoby]

In 7080:

Sub-Actions: add is_string() checks to bbp_get/post_request()` functions.

This commit prevents possible PHP warnings when action global variables are sent over as an array using the [] URI syntax, which is not supported.

Props dd32.

(In trunk, for 2.7.0.)

Fixes #3373.

[johnjamesjacoby]

In 7081:

Sub-Actions: add is_string() checks to bbp_get/post_request()` functions.

This commit prevents possible PHP warnings when action global variables are sent over as an array using the [] URI syntax, which is not supported.

Props dd32.

(In branches/2.6, for 2.6.5.)

Fixes #3373.