convert: avoid svn log retrieval process cleanup
With huge history (like kdelibs), the process termination suddenly consumes a
lot of memory (from 700M to 1.3G+). Since the job is done, clean termination is
not required, just exit.
#!/bin/sh
mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m test -d "1000000 0"
hg history
hg manifest --debug
hg cat a
hg verify