Hash Update openwrt.gns3a

[lethedata]

Update hashes for openwrt-18.06.5 and openwrt-18.06.2 based hashes from download links.

Before submitting a pull request, please check the following.

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When updating an existing appliance:

• [x] The new version is on top. (No new version added)
• [x] The filenames in the "images" section are unique, to avoid appliances / version overwriting each other. (Hash change only)

• [x] If you forked the repo, running check.py doesn't drop any errors for the updated file.

[lethedata]

Same as https://github.com/GNS3/gns3-server/pull/2274 but to the correct repo.

[grossmj]

Thank you :)