Fix random build failure on nuxeo-review-workflows-dashboards

     [exec] bower paper-dialog#1.1.0                          resolved git://github.com/PolymerElements/paper-dialog.git#1.1.0
     [exec] bower nuxeo#0.9.0                                 resolved https://github.com/nuxeo/nuxeo-js-client.git#0.9.0
     [exec] bower paper-dropdown-menu#1.4.2                    extract archive.tar.gz
     [exec] bower paper-dialog-behavior#1.2.7                 resolved git://github.com/PolymerElements/paper-dialog-behavior.git#1.2.7
     [exec] bower paper-fab#1.2.1                              extract archive.tar.gz
     [exec] events.js:160
     [exec]       throw er; // Unhandled 'error' event
     [exec]       ^
     [exec] 
     [exec] Error: ENOENT: no such file or directory, open '/tmp/jenkins/bower/61ae04c910cc77fdacea78d9cefc90aa-21091-Ju6nC1/archive.tar.gz.69909623'
     [exec]     at Error (native)
     [exec] bower paper-header-panel#1.1.7                     extract archive.tar.gz
     [exec] bower paper-icon-button#1.1.3                      extract archive.tar.gz
     [exec] bower paper-scroll-header-panel#1.0.16            download https://github.com/PolymerElements/paper-scroll-header-panel/archive/v1.0.16.tar.gz