fix the CI build flag

appveyor.yml

@@ -141,7 +141,7 @@ build_script:
 - cmd: |
     "%PYTHON%/python.exe" -m pip install --upgrade pip
     "%PYTHON%/python.exe" -m pip install --upgrade setuptools
-    set "CI_BUILD=True" && "%PYTHON%/python.exe" -m pip wheel --wheel-dir=%cd%\dist . --verbose
+    set "CI_BUILD=1" && "%PYTHON%/python.exe" -m pip wheel --wheel-dir=%cd%\dist . --verbose
 
 before_test:
 - ps: |

setup.py

@@ -14,7 +14,7 @@ def main():
     os.chdir(os.path.dirname(os.path.abspath(__file__)))
 
     CI_BUILD = os.environ.get("CI_BUILD", "False")
-    is_CI_build = True if CI_BUILD == "True" else False
+    is_CI_build = True if CI_BUILD == "1" else False
     cmake_source_dir = "opencv"
     minimum_supported_numpy = "1.13.1"
     build_contrib = get_build_env_var_by_name("contrib")