Back-porting change from 2.3 (should have been patched into 2.2 originally)

Updated XSSI Json Hijacking Caution

Only methods that respond to GET requests are vulnerable to XSSI 'JSON Hijacking'. POST requests remain unaffected.
(cherry picked from commit b84559133e5daf2caa609e1f7a633a8c42e271e7)
Back-porting change from 2.3 (should have been patched into 2.2 originally)

[#2710] Fixing whitespace
(cherry picked from commit f8ace43cdee888c8856c9225f702561845a2e746)