ignore .git directory at docker build
ignore .git directory at docker build

- COPY copies the .git directory to the image. The docker build then
  stops with this error:

=> Errors while initializing project:

While building package wekan-cfs-data-man:
error: couldn't install npm package request@https://github.com/wekan/request:
Command failed:
/home/wekan/.meteor/packages/meteor-tool/.2.2.0.1j8auib.qcbe++os.linux.x86_64+web.browser+web.browser.legacy+web.cordova/mt-os.linux.x86_64/dev_bundle/bin/npm
install https://github.com/wekan/request
npm ERR! Error while executing:
npm ERR! /usr/bin/git ls-remote -h -t https://github.com/wekan/request.git
npm ERR!
npm ERR! fatal: not a git repository: /home/wekan/app/../.git/modules/src
npm ERR!
npm ERR! exited with error code: 128

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/wekan/.npm/_logs/2021-06-10T12_54_02_777Z-debug.log
npm ERR! Error while executing:
npm ERR! /usr/bin/git ls-remote -h -t https://github.com/wekan/request.git
npm ERR!
npm ERR! fatal: not a git repository: /home/wekan/app/../.git/modules/src
npm ERR!
npm ERR! exited with error code: 128

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/wekan/.npm/_logs/2021-06-10T12_54_02_777Z-debug.log

wekan/wekan,wekan/wekan,wekan/wekan,wekan/wekan,wekan/wekan