Added empty input data error catching for PCA analysis.
LineGraph.js has been loaded dynamically via its gsp. It shouldn't be loaded here.
:nail_care:
Merge pull request #29 from thehyve/issues/117-PCA-empty-data-error-catching

Added empty input data error catching for PCA analysis.
Bugfix. Sloppy comma omission.

My bad.
Merge branch 'master' into features/UAT_108_LineGraph_Group_HighDim