Description of silent_variable_failure is incorrect

[Aymeric Augustin]

​https://docs.djangoproject.com/en/1.7/ref/templates/api/#variables-and-lookups says that when an exception is swallowed because it has a silent_variable_failure attribute set to True, the variable that failed is rendered as the empty string.

Actually it's rendered as settings.TEMPLATE_STRING_IF_INVALID which seems to be the correct behavior.

[Tim Graham <timograham@…>]

In e7cb4f2fbaff7996fb48e9c79aa0ec454abcf8f7:

Fixed #23736 -- Corrected the description of the value that silent_variable_failure uses.

Thanks Aymeric Augustin for the report.

[Tim Graham <timograham@…>]

In f2de56223540c1e728c82baf206ffa6e6f285eab:

[1.7.x] Fixed #23736 -- Corrected the description of the value that silent_variable_failure uses.

Thanks Aymeric Augustin for the report.

Backport of e7cb4f2fba from master

[Tim Graham <timograham@…>]

In 89df9d244d47d7c6cf29bd482a791dd4c684e237:

[1.6.x] Fixed #23736 -- Corrected the description of the value that silent_variable_failure uses.

Thanks Aymeric Augustin for the report.

Backport of e7cb4f2fba from master