Increase Salt Fomulas tests pipeline timeout

	- 2 hours are not enough for some child jobs to finish
	- Example: https://ci.mcp.mirantis.net/job/test-salt-formula-cinder-latest/193/console

Change-Id: I573ca348b8985140b20d9c6842ccb0ab7782b340
diff --git a/test-salt-formulas-pipeline.groovy b/test-salt-formulas-pipeline.groovy
index 45eeef8..52c7d79 100644
--- a/test-salt-formulas-pipeline.groovy
+++ b/test-salt-formulas-pipeline.groovy
@@ -62,7 +62,7 @@
   ]
 }
 
-timeout(time: 2, unit: 'HOURS') {
+timeout(time: 4, unit: 'HOURS') {
   node(slaveNode) {
     try {
       if (fileExists("tests/build")) {