histedit: rip out mysterious catch-all ignore curses.error handler

I have no idea why this was here, and ripping it out doesn't obviously
break anything for me (tests all pass, I can poke around chistedit UI
a bit without issue), so I'm thinking we should rip it out and see if
we get bug reports.

Differential Revision: https://phab.mercurial-scm.org/D9855

hgext/histedit.py

@@ -1623,7 +1623,6 b' pgup/K: move patch up, pgdn/J: move patc'
     stdscr.clear()
     stdscr.refresh()
     while True:
-        try:
             oldmode, unused = state[b'mode']
             if oldmode == MODE_INIT:
                 changemode(state, MODE_RULES)
@@ -1678,8 +1677,6 b' pgup/K: move patch up, pgdn/J: move patc'
                 curses.doupdate()
                 # done rendering
                 ch = encoding.strtolocal(stdscr.getkey())
-        except curses.error:
-            pass
 
 
 def _chistedit(ui, repo, freeargs, opts):