Fix #37122: Text Editor: New Open-Shortcut different from Text > Open Text Block

Seems no user counter tricks are needed from r23598.

Also, r33453 is obviously wrong, because new ID's user counter is 1,
and could not exceed this value.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk@60820 954f8c5b-7b00-dc11-b283-0030488c597c