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

1 files changed, 0 insertions, 1 deletions

diff --git a/collectors/python.d.plugin/chrony/chrony.chart.py b/collectors/python.d.plugin/chrony/chrony.chart.py
index fd01d4e855..07fc3d1fcc 100644
--- a/collectors/python.d.plugin/chrony/chrony.chart.py
+++ b/collectors/python.d.plugin/chrony/chrony.chart.py
@@ -8,7 +8,6 @@ from bases.FrameworkServices.ExecutableService import ExecutableService
 # default module values (can be overridden per job in `config`)
 update_every = 5
 priority = 60000
-retries = 10
 
 # charts order (can be overridden if you want less charts, or different order)
 ORDER = ['system', 'offsets', 'stratum', 'root', 'frequency', 'residualfreq', 'skew']