BIM: fix invalid converesion of button to int

src/Mod/BIM/bimcommands/BimLibrary.py

@@ -536,7 +536,7 @@ class BIM_Library_TaskPanel:
 
         from PySide import QtGui
 
-        return int(QtGui.QDialogButtonBox.Close)
+        return QtGui.QDialogButtonBox.Close
 
     def reject(self):
 

src/Mod/BIM/bimcommands/BimPreflight.py

@@ -158,7 +158,7 @@ class BIM_Preflight_TaskPanel:
     def getStandardButtons(self):
         from PySide import QtCore, QtGui
 
-        return int(QtGui.QDialogButtonBox.Close)
+        return QtGui.QDialogButtonBox.Close
 
     def reject(self):
         from PySide import QtCore, QtGui

src/Mod/BIM/bimcommands/BimWindows.py

@@ -71,7 +71,7 @@ class BIM_Windows_TaskPanel:
     def getStandardButtons(self):
         from PySide import QtGui
 
-        return int(QtGui.QDialogButtonBox.Close)
+        return QtGui.QDialogButtonBox.Close
 
     def reject(self):
         FreeCADGui.Control.closeDialog()