Fix broken pipe v0.5.1 (#679)

* Fix broken pipe error

* updates

azure-pipelines.yml

@@ -33,7 +33,7 @@ jobs:
     displayName: 'Built-in tuners / assessors tests'
   - script: |
       cd test
-      PATH=$HOME/.local/bin:$PATH python3 config_test.py --ts local
+      PATH=$HOME/.local/bin:$PATH python3 config_test.py --ts local --local_gpu
     displayName: 'Examples and advanced features tests on local machine'
   - script: |
       cd test

src/sdk/pynni/nni/common.py

@@ -44,13 +44,10 @@ _time_format = '%Y-%m-%d %H:%M:%S'
 class _LoggerFileWrapper(TextIOBase):
     def __init__(self, logger_file):
         self.file = logger_file
-        self.orig_stdout = sys.stdout
 
     def write(self, s):
         if s != '\n':
             time = datetime.now().strftime(_time_format)
-            self.orig_stdout.write(s + '\n')
-            self.orig_stdout.flush()
             self.file.write('[{}] PRINT '.format(time) + s + '\n')
             self.file.flush()
         return len(s)