Refine testcase to fix Python36 issue

Author: jondy

src/examples/testmod/hello.py

@@ -33,7 +33,7 @@
 try:
   __wraparmor__(main)
 except Exception as e:
-  print(e)
+  print('__wraparmor__ can not be called out of decorator')
 
 # Check filename in trackback
 queens.test_exception()

tests/system-test.sh

@@ -318,7 +318,7 @@ check_file_content $PROPATH/dist/queens.py '__pyarmor__(__name__'
 (cd $PROPATH/dist; $PYTHON hello.py >result.log 2>&1 )
 check_file_content $PROPATH/dist/result.log 'Found 92 solutions'
 check_file_content $PROPATH/dist/result.log 'index out of range'
-check_file_content $PROPATH/dist/result.log 'error return without exception set'
+check_file_content $PROPATH/dist/result.log '__wraparmor__ can not be called out of decorator'
 check_file_content $PROPATH/dist/result.log 'The value of __file__ is OK'
 check_file_content $PROPATH/dist/result.log '<frozen \[queens\]>'