Twenty Fourteen: simplify header image check, props obenland. See #25400.
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git-svn-id: http://core.svn.wordpress.org/trunk@25521 1a063a9b-81f0-0310-95a4-ce76da25c4cd
When is_main_query() is called during the pre_get_posts hook, issue _doing_it_wrong().

The is_main_query() WP_Query method should be used in these instances instead.
see #23329.

Built from https://develop.svn.wordpress.org/trunk@25605


git-svn-id: http://core.svn.wordpress.org/trunk@25522 1a063a9b-81f0-0310-95a4-ce76da25c4cd