[master] use posix-compatible shell in system tests

3839.	[test]		Use only posix-compatible shell in system tests.
			[RT #35625]

bin/tests/system/staticstub/ns3/sign.sh

@@ -14,8 +14,6 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-# $Id: sign.sh,v 1.3 2010/12/17 00:57:39 marka Exp $
-
 SYSTEMTESTTOP=../..
 . $SYSTEMTESTTOP/conf.sh
 
@@ -23,7 +21,7 @@ zone=example.
 infile=example.db.in
 zonefile=example.db
 
-(cd ../ns4 && sh -e sign.sh )
+(cd ../ns4 && $SHELL -e sign.sh )
 
 cp ../ns4/dsset-sub.example. .
 

bin/tests/system/staticstub/prereq.sh

@@ -14,4 +14,7 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-exec sh ../testcrypto.sh
+SYSTEMTESTTOP=..
+. $SYSTEMTESTTOP/conf.sh
+
+exec $SHELL ../testcrypto.sh

bin/tests/system/staticstub/setup.sh

@@ -23,4 +23,4 @@ sed 's/EXAMPLE_ZONE_PLACEHOLDER/zone "example" { type master; file "example.db.s
 
 test -r $RANDFILE || $GENRANDOM 400 $RANDFILE
 
-cd ns3 && sh -e sign.sh
+cd ns3 && $SHELL -e sign.sh