patchbomb: fix 'echo -en' bashism in test-patchbomb
The echo command doesn't accept options in some shells.
printf is required by the SUSv2 (Single UNIX Specification v2).
#!/bin/sh
echo '[Section]' >> $HGRCPATH
echo 'KeY = Case Sensitive' >> $HGRCPATH
echo 'key = lower case' >> $HGRCPATH
hg showconfig Section