tests/test-config-env.py.out

mpatch: ensure fragment start isn't past the end of orig (SEC)

Caught by oss-fuzz fuzzer during development.

This defect is OVE-20180430-0004. A CVE has not been obtained as of
this writing.

pager.pager=p0 # $TESTTMP/sysrc:4
ui.editor=e1 # $TESTTMP/userrc:2

pager.pager=p2 # $PAGER
ui.editor=e1 # $TESTTMP/userrc:2