[gui][displayComponentsWidget] Fix bug when resetting dimensions

darfix/gui/displayComponentsWidget.py

@@ -316,5 +316,7 @@ class PlotRockingCurves(qt.QMainWindow):
         self._cb.addItem(dimension)
 
     def resetDimensions(self):
-        for i in range(1, self._cb.count()):
-            self._cb.removeItem(i)
+        oldState = self._cb.blockSignals(True)
+        self._cb.clear()
+        self._cb.addItem("None")
+        self._cb.blockSignals(oldState)