Fix UmbrellaException on workflow screens

Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError): this._jsPlumb.instance.continuousAnchorFactory is undefined

Caused by: com.google.gwt.user.client.ui.AttachDetachException: One or more exceptions caught, see full set in UmbrellaException#getCauses
    at Unknown.ue(Unknown Source)
    at Unknown.uj(Unknown Source)
    at Unknown.Oz(Unknown Source)
    at Unknown.Rz(Unknown Source)
    at Unknown.Vzb(Unknown Source)
    at Unknown.Xzb(Unknown Source)
    at Unknown.Pyb(Unknown Source)
Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError): Cannot read property 'reset' of undefined
 stack: TypeError: Cannot read property 'reset' of undefined
    at deleteEveryEndpoint (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/jquery.jsPlumb-1.5.1-min.js:1:37273)
    at Object.$4d [as te] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8443:19617)
    at vyb (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:7683:192)
    at Object.Hyb [as re] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8407:22978)
    at Object.$zb [as Ee] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8407:25342)
    at Xzb (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:7624:91)
    at Object.Pyb [as oe] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8407:23341)
    at vyb (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:7683:185)
    at Object.Hyb [as re] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8407:22978)
    at Object.$zb [as Ee] (https://connect.nuxeo.com/nuxeo/site/studio/ide/studio/DBB8BA6ADCBD0BD5BDBEB4E9AEBFFA8D.cache.html:8407:25342)
    at Unknown.deleteEveryEndpoint(Unknown Source)
    at Unknown.$4d(Unknown Source)