docs/configuration: Fixed typo CELERY_SOFT_TASK_TIME_LIMIT -> CELERY_TASK_SOFT_TIME_LIMIT. Closes #214. Thanks to Lifto

docs/configuration.rst

@@ -745,9 +745,9 @@ CELERYD_TASK_TIME_LIMIT
 Task hard time limit in seconds.  The worker processing the task will
 be killed and replaced with a new one when this is exceeded.
 
-.. setting:: CELERYD_SOFT_TASK_TIME_LIMIT
+.. setting:: CELERYD_TASK_SOFT_TIME_LIMIT
 
-CELERYD_SOFT_TASK_TIME_LIMIT
+CELERYD_TASK_SOFT_TIME_LIMIT
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Task soft time limit in seconds.