mr_create: check for empty msg before acting

When creating a merge request in draft mode the message size wasn't being
considered: if it was empty, the code would not check and panic due to a
"slice bounds out of range". This patch basically moves the check for
message existence before the actual manipulation code happens.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>

cmd/mr_create.go

@@ -218,6 +218,10 @@ func runMRCreate(cmd *cobra.Command, args []string) {
 		}
 	}
 
+	if title == "" {
+		log.Fatal("aborting MR due to empty MR msg")
+	}
+
 	linebreak, _ := cmd.Flags().GetBool("force-linebreak")
 	if linebreak {
 		body = textToMarkdown(body)
@@ -239,10 +243,6 @@ func runMRCreate(cmd *cobra.Command, args []string) {
 	squash, _ := cmd.Flags().GetBool("squash")
 	allowCollaboration, _ := cmd.Flags().GetBool("allow-collaboration")
 
-	if title == "" {
-		log.Fatal("aborting MR due to empty MR msg")
-	}
-
 	mrURL, err := lab.MRCreate(sourceProjectName, &gitlab.CreateMergeRequestOptions{
 		SourceBranch:       &branch,
 		TargetBranch:       gitlab.String(targetBranch),