python.d.plugin update (#4936)

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##### Summary
Fix: #4756

`python.d.plugin` updates:
  * remove `retries` option 
  * make `penalty` configurable (enabled by default, max is 10 minutes)

> penalty indicates whether to apply penalty to update_every in case of failures.
> Penalty will increase every 5 failed updates in a row. Maximum penalty is 10 minutes.
> penalty: yes

##### Component Name

`python.d.plugin`

##### Additional Information

collectors/python.d.plugin/postgres/postgres.chart.py

@@ -19,7 +19,6 @@ from bases.FrameworkServices.SimpleService import SimpleService
 # default module values
 update_every = 1
 priority = 60000
-retries = 60
 
 METRICS = {
     'DATABASE': [

collectors/python.d.plugin/postgres/postgres.conf

@@ -27,11 +27,9 @@
 # If unset, the default for python.d.plugin is used.
 # priority: 60000
 
-# retries sets the number of retries to be made in case of failures.
-# If unset, the default for python.d.plugin is used.
-# Attempts to restore the service are made once every update_every
-# and only if the module has collected values in the past.
-# retries: 60
+# penalty indicates whether to apply penalty to update_every in case of failures.
+# Penalty will increase every 5 failed updates in a row. Maximum penalty is 10 minutes.
+# penalty: yes
 
 # autodetection_retry sets the job re-check interval in seconds.
 # The job is not deleted if check fails.
@@ -58,7 +56,7 @@
 #                             # JOBs sharing a name are mutually exclusive
 #     update_every: 1         # the JOB's data collection frequency
 #     priority: 60000         # the JOB's order on the dashboard
-#     retries: 60             # the JOB's number of restoration attempts
+#     penalty: yes            # the JOB's penalty
 #     autodetection_retry: 0  # the JOB's re-check interval in seconds
 #
 # A single connection is required in order to pull statistics.