large json input object cause double run tasks

[guzzijones]

SUMMARY

Large json inputs cause double runs of tasks when passed as input.
Provide a quick summary of your bug report.

STACKSTORM VERSION

lastest master

OS, environment, install method

ubuntu / development install instructions
python 3 build

Steps to reproduce the problem

1. git clone https://github.com/guzzijones/st2doublerunbug.git
2. install pack into stackstorm
3. open st2web. go to actions
4. open bug | parent action
5. paste contents of notification.json as input param notification
6. click run and wait until it is uploaded. takes about 1 min
7. watch tasks get run 2 times.

Expected Results

It should only run tasks one time

Actual Results

It runs the tasks 2 times

fix implemented

#4886
This works for me, if there is a better solution let me know.