Increase to 30 seconds wait time before trying to merge previous MRs

When a queued MR (previously blocked by another MR causing conflicts) is not blocked anymore, Gitlab needs time to correctly report the status of that MR. 5 seconds wasn't always enough. Ref #24

src/main/java/service/GitLabService.java

@@ -194,8 +194,8 @@ private void mergePreviousAutoMr(CascadeResult result, String gitlabEventUUID, L
 					Log.infof("GitlabEvent: '%s' | Found auto merge request between '%s' and '%s' - iid: '%s', mergeWhenPipelineSucceeds: '%s'", gitlabEventUUID, prevSourceBranch, sourceBranch, mr.getIid(), mr.getMergeWhenPipelineSucceeds());
 					if (mr.getMergeWhenPipelineSucceeds() == Boolean.FALSE) {
 						if (mr.getHasConflicts() != null && mr.getHasConflicts()) {
-							//wait 5 seconds in order for GitLab to have time to update the merge request status
-							sleepSeconds(5);
+							// wait some seconds in order for GitLab to have time to update the merge request status
+							sleepSeconds(30);
 							mr = getExistingMr(gitlabEventUUID, mr);
 						}
 						MergeRequestResult mrResult = acceptAutoMergeRequest(gitlabEventUUID, mr);