About page RTL fixes.

Merges [30951] and [30952] to the 4.1 branch.

props helen, alex-ye.
fixes #30743, #30748.

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git-svn-id: http://core.svn.wordpress.org/branches/4.1@30945 1a063a9b-81f0-0310-95a4-ce76da25c4cd