cubicweb-inlinedit #2841851 cleanup unused cancel_reledit controller [validation pending]

it sits there, unused and also manifestly wrong (references unexisting appobject)

prioritynormal
typebug
done in1.0.2
load0.100
load left0.000
closed by#df7bcc321b30 [views/controller,js] kill cancel_reledit controller (closes #2841851)
patch[js] kill cancel_reledit controller (closes #2841851) [applied]