hgview #93422 stange behaviour when "finding" an empty string [validation pending]

open the find centext and click on `find next` without any characters in the input area.
Hgview goes throught the overall repository and display the overall data which can be very annoying on heavy repo.

done in1.6.0
load left0.000
closed by#29279e6d322c [qt] fix: do nothing if the entry of ``find`` is empty (closes #93422)