Fix python.v2.fluid arg parse (#6055)

* fix python gflags init

* format code

python/paddle/v2/fluid/__init__.py

@@ -36,7 +36,8 @@ def __read_gflags_from_env__():
     read_env_flags = ['use_pinned_memory']
     if core.is_compile_gpu():
         read_env_flags.append('fraction_of_gpu_memory_to_use')
-    core.init_gflags(sys.argv + ["--tryfromenv=" + ",".join(read_env_flags)])
+    core.init_gflags([sys.argv[0]] +
+                     ["--tryfromenv=" + ",".join(read_env_flags)])
 
 
 __read_gflags_from_env__()