test-gpg: suppress secure memory warning

Some platforms (Solaris for one) does not support secure memory and
would give a warning.

tests/test-gpg

@@ -1,28 +1,28 b''
 #!/bin/sh
 
 "$TESTDIR/hghave" gpg || exit 80
 
 cat <<EOF >> $HGRCPATH
 [extensions]
 gpg=
 
 [gpg]
-cmd=gpg --no-permission-warning --homedir $TESTDIR/gpg
+cmd=gpg --no-permission-warning --no-secmem-warning --homedir $TESTDIR/gpg
 EOF
 
 hg init r
 cd r
 echo foo > foo
 hg ci -Amfoo
 
 echo '% no signatures'
 hg sigs
 
 echo '% hg sign 0'
 hg sign 0
 
 echo '% hg sigs'
 hg sigs
 
 echo '% hg sigcheck 0'
 hg sigcheck 0