Increase the timeout of test_pe_seresnext (#15621)

* chang the timeout of test_pe_resnet
test=develop

* follow comment
test=develop

python/paddle/fluid/tests/unittests/CMakeLists.txt

@@ -110,6 +110,10 @@ py_test_modules(test_parallel_executor_transformer MODULES test_parallel_executo
 if(NOT APPLE)
     py_test_modules(test_image_classification_resnet MODULES test_image_classification_resnet SERIAL)
 endif()
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    # change the timeout from 600 to 900, because in debug mode, this test need more time.
+    set_tests_properties(test_image_classification_resnet PROPERTIES TIMEOUT 900)
+endif()
 
 if (WITH_NGRAPH)
     add_subdirectory(ngraph)