Remove includsion of contrail-charts.css from dashboard.html file
Remove includsion of contrail-charts.css from dashboard.html file

As contrail-charts.css is included as part of contrail.thirdparty.unified.css,
remove from dashboard.html

Change-Id: I739d6daa8e6e25395bdbd3f183ad503ac26e6b05
Related-Bug: #1712558

biswajit-mandal/contrail-web-core,biswajit-mandal/contrail-web-core,biswajit-mandal/contrail-web-core