reverted capa module after accidental changes

common/lib/xmodule/xmodule/capa_module.py

@@ -266,7 +266,7 @@ class CapaModule(XModule):
                 # Prepend a scary warning to the student
                 warning  = '<div class="capa_reset">'\
                            '<h2>Warning: The problem has been reset to its initial state!</h2>'\
-                          'The problem\'s state was corrupted by an invalid submission. '\
+                           'The problem\'s state was corrupted by an invalid submission. ' \
                            'The submission consisted of:'\
                            '<ul>'
                 for student_answer in student_answers.values():