jenkins-*.sh: set -x

Also move the options from the shebang line to the body of the script, so that
they take effect even if somebody explicitly runs "bash jenkins.sh"

jenkins-flake8.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/bin/bash
+
+set -eux
 
 : ${WORKSPACE:="$(pwd)"}
 

jenkins-postgres.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/bin/bash
+
+set -eux
 
 : ${WORKSPACE:="$(pwd)"}
 

jenkins-sqlite.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/bin/bash
+
+set -eux
 
 : ${WORKSPACE:="$(pwd)"}
 

jenkins-unittests.sh

@@ -1,4 +1,6 @@
-#!/bin/bash -eu
+#!/bin/bash
+
+set -eux
 
 : ${WORKSPACE:="$(pwd)"}