[exim-dev] Typo spec.txt 4.52 section 5.3 -odf

Typo in spec.txt for Exim 4.52, section 5.3, -odf

"exists" at the end of the first sentence of the last paragraph should be
"exits".

As is:

If there is a temporary delivery error during foreground delivery, the
message is left on the queue for later delivery, and the original reception
process exists.


--John (who happened to be searching for "exists")