add missing return_output=True argument when fetching script content

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>

lib/cdist/exec/local.py

@@ -122,7 +122,7 @@ class Local(object):
             else:
                 subprocess.check_call(command, env=env)
         except subprocess.CalledProcessError as error:
-            script_content = self.run(["cat", script])
+            script_content = self.run(["cat", script], return_output=True)
             self.log.error("Code that raised the error:\n%s", script_content)
             raise LocalScriptError(script, command, script_content)
         except EnvironmentError as error:

lib/cdist/exec/remote.py

@@ -148,7 +148,7 @@ class Remote(object):
             else:
                 subprocess.check_call(command)
         except subprocess.CalledProcessError as error:
-            script_content = self.run(["cat", script])
+            script_content = self.run(["cat", script], return_output=True)
             self.log.error("Code that raised the error:\n%s", script_content)
             raise RemoteScriptError(script, command, script_content)
         except EnvironmentError as error: