changed shell delimiters for csh

fixes #13459

lib/ansible/plugins/shell/csh.py

@@ -24,6 +24,8 @@ class ShellModule(ShModule):
     # How to end lines in a python script one-liner
     _SHELL_EMBEDDED_PY_EOL = '\\\n'
     _SHELL_REDIRECT_ALLNULL = '>& /dev/null'
+    _SHELL_SUB_LEFT = '"`'
+    _SHELL_SUB_RIGHT = '`"'
 
     def env_prefix(self, **kwargs):
         return 'env %s' % super(ShellModule, self).env_prefix(**kwargs)