cubicweb #2888538 bad help message for schemadiff command [validation pending]

the message appears on several lines (try cubicweb-ctl -h)

prioritynormal
typebug
done in3.17.1
load0.100
load left0.000
closed by#0f2fad7a92d4 [cw-ctl] fix help message for schemadiff In global help (closes #2888538)
patch[cw-ctl] improve error message of schemadiff command (closes #2888538) [applied]