Fix fill method os_install_linux_ver.

pym/cl_fill_install.py

@@ -672,7 +672,7 @@ class fillVars(object, glob_attr):
                                   self.Get('cl_image_path'),
                                   self.Get('os_install_arch_machine'),
                                   self.Get('os_install_linux_shortname'))
-        if not imagename:
+        if not imagename and self.Get('cl_action') != 'merge':
             return ""
         d = DistributiveRepository()._getfromcontent(imagename)
         if "linuxver" in d and d['linuxver'] != "0":