editmerge: dequote other use of $ED

We want to support editors with parameters, eg EDITOR="vim -O" or whatever.
So remove the quotes from around $ED and assume that the editor variable is
properly escaped already.

contrib/editmerge

@@ -1,58 +1,58
 #!/usr/bin/env bash
 # A simple script for opening merge conflicts in the editor.
 # Use the following Mercurial settings to enable it.
 #
 # [ui]
 # merge = editmerge
 #
 # [merge-tools]
 # editmerge.args=$output
 # editmerge.check=changed
 # editmerge.premerge=keep
 
 FILE="$1"
 
 getlines() {
   grep -n "^<<<<<<" "$FILE" | cut -f1 -d:
 }
 
 # editor preference loosely based on https://mercurial-scm.org/wiki/editor
 # hg showconfig is at the bottom though, since it's slow to run (0.15 seconds)
 ED="$HGEDITOR"
 if [ "$ED" = "" ] ; then
   ED="$VISUAL"
 fi
 if [ "$ED" = "" ] ; then
   ED="$EDITOR"
 fi
 if [ "$ED" = "" ] ; then
   ED="$(hg showconfig ui.editor)"
 fi
 if [ "$ED" = "" ] ; then
   echo "merge failed - unable to find editor"
   exit 1
 fi
 
 if [ "$ED" = "emacs" ] || [ "$ED" = "nano" ] || [ "$ED" = "vim" ] ; then
   FIRSTLINE="$(getlines | head -n 1)"
   PREVIOUSLINE=""
 
   # open the editor to the first conflict until there are no more
   # or the user stops editing the file
   while [ ! "$FIRSTLINE" = "" ] && [ ! "$FIRSTLINE" = "$PREVIOUSLINE" ] ; do
-    "$ED" "+$FIRSTLINE" "$FILE"
+    $ED "+$FIRSTLINE" "$FILE"
     PREVIOUSLINE="$FIRSTLINE"
     FIRSTLINE="$(getlines | head -n 1)"
   done
 else
   $ED "$FILE"
 fi
 
 # get the line numbers of the remaining conflicts
 CONFLICTS="$(getlines | sed ':a;N;$!ba;s/\n/, /g')"
 if [ ! "$CONFLICTS" = "" ] ; then
   echo "merge failed - resolve the conflicts (line $CONFLICTS) then use 'hg resolve --mark'"
   exit 1
 fi
 
 exit 0