Fix for bug #1078 : It have to set an initial value for the project_id, otherwise on empty project in the form cause that, the last of the previously set project number will remain. So, set to zero before it will be untouched or set to the selected projectnumber.
(grafted from a7e36729d5c4af6a8eb438f477dfbb82e96eac8c)

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extra : source : a7e36729d5c4af6a8eb438f477dfbb82e96eac8c
Update Changelog.
(grafted from f6724e97a6c5c084ce648fdbc60afeb7d042f64b)

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extra : source : f6724e97a6c5c084ce648fdbc60afeb7d042f64b