Add make command update-translations for update translations from crodwin

[lunny]

Also I have sent a PR to ini package, see go-ini/ini#110. After these two this PR merged, it's easy to update the translations to local and create a translation PR is easy too. @lafriks

[lafriks]

This code did not work for me as tar can not extract files from zip archives.
How about such code (it does work even without changes in go-ini):

.PHONY: update-translations
update-translations:
	mkdir -p ./translations
	cd ./translations && curl -L https://crowdin.com/download/project/gitea.zip > gitea.zip && unzip gitea.zip
	rm ./translations/gitea.zip
	$(SED_INPLACE) -e 's/="/=/g' -e 's/"$$//g' ./translations/*.ini
	$(SED_INPLACE) -e 's/\\"/"/g' ./translations/*.ini
	mv ./translations/*.ini ./options/locale/
	rmdir ./translations

Also changed from wget to curl as curl is also used in other places in Makefile

[lafriks]

Also crowdin zip file needs to be regenerated as in Swedish translation there was error that did not allow gitea to start (I fixed it but zip file still contains old broken translation)

[lunny]

@lafriks before download, we have to click the build the project on the UI. I haven't find any HTTP method except API key to do that.

[lunny]

@lafriks done.

[lafriks]

Just thought that it could be more optimized by piping curl output directly to unzip and than rm gitea.zip is also not needed:

	cd ./translations && curl -L https://crowdin.com/download/project/gitea.zip | unzip

but otherwise LGTM

[lunny]

@lafriks It didn't work on macOS

[lafriks]

oh well, if it is not working on macos than just leave how it is :)

[ethantkoenig]

LGTM