Use the stable/dev branching model for QtSerialPort after the move

Change-Id: Ia5964623e283e54c44e09682b18321e5a358bf6a
Reviewed-by: Simo Fält <simo.falt@digia.com>
Reviewed-by: Janne Anttila <janne.anttila@digia.com>

scripts/jenkins/ci.cfg

@@ -453,10 +453,15 @@ Enabled = 1
 GerritUrl = "ssh://codereview.qt-project.org:29418/qt/qtx11extras"
 GerritBranch = master
 
-[QtSerialPort_master_Integration]
+[QtSerialPort_dev_Integration]
 Enabled = 1
 GerritUrl = "ssh://codereview.qt-project.org:29418/qt/qtserialport"
-GerritBranch = master
+GerritBranch = dev
+
+[QtSerialPort_stable_Integration]
+Enabled = 1
+GerritUrl = "ssh://codereview.qt-project.org:29418/qt/qtserialport"
+GerritBranch = stable
 
 [QtWinExtras_dev_Integration]
 Enabled = 1