python-flask: fix s/flash/flask/ _DEPENDENCIES typo

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/python-flask/python-flask.mk

@@ -10,6 +10,6 @@ PYTHON_FLASK_SITE = http://pypi.python.org/packages/source/F/Flask
 PYTHON_FLASK_SETUP_TYPE = setuptools
 PYTHON_FLASK_LICENSE = BSD-3c
 PYTHON_FLASK_LICENSE_FILES = LICENSE
-PYTHON_FLASH_DEPENDENCIES = python-werkzeug python-jinja2 python-itsdangerous
+PYTHON_FLASK_DEPENDENCIES = python-werkzeug python-jinja2 python-itsdangerous
 
 $(eval $(python-package))