cubicweb-vcreview #1696802 change subject of notification email [validation pending]

It would be nice if:

[patch appliqué] cwuser.diff (docaster patches)

could be changed to:

[docaster] patch applied: cwuser.diff

in order to match the format:

[<projet>] <action>: <detail...>
prioritynormal
typeenhancement
done in0.6.0
load left0.000
closed by#6500c415afca [hooks] change email subjects to match format "[project] action: detail" (closes #1696802)