Fix incorrect documentation URL in phpDoc

[maks-rafalko]

Old URL throws 404 error.
New correct URL is http://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-geo-point-type.html

[coveralls]

Coverage remained the same at 84.58% when pulling d309603 on borNfreee:patch-1 into 59c1a4c on ruflin:master.

[im-denisenko]

There are 303 other uses of "elasticsearch.org" across all library. Perhaps you could check them too?

You could locate them using:

find {ansible,lib,test} -type f  | xargs grep -n 'elasticsearch.org'

[ruflin]

Agree, would be nice to have it directly changed everywhere. @borNfreee Can you add this change?