Bump clipboard from 1.7.1 to 2.0.4

Bumps [clipboard](https://github.com/zenorocha/clipboard.js) from 1.7.1 to 2.0.4.
- [Release notes](https://github.com/zenorocha/clipboard.js/releases)
- [Commits](zenorocha/clipboard.js@v1.7.1...v2.0.4)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

package-lock.json

@@ -26,7 +26,7 @@
     "backbone": "^1.2.3",
     "blueimp-md5": "^2.7.0",
     "bootstrap": "^3.3.7",
-    "clipboard": "^1.7.1",
+    "clipboard": "^2.0.4",
     "css-vars-ponyfill": "^1.7.2",
     "davclient.js": "git+https://github.com/owncloud/davclient.js.git#0.1.2",
     "dompurify": "^1.0.4",