Problem in generation of pdf with images

[saramonzon]

Warning in httpd log that could be related:
[Wed Jun 20 17:18:36 2018] [error] [client 10.15.60.49] File does not exist: /srv/iSkyLIMS/static/iSkyLIMS_common_static/vendor/swiper/js/maps
[Wed Jun 20 17:18:44 2018] [error] [client 10.15.60.49] /srv/iSkyLIMS/virtualenv/lib/python3.6/site-packages/weasyprint/text.py:28: UserWarning: There are known rendering problems with Cairo <= 1.14.0, referer: http://flavia.isciii.es/drylab/service_request_internal_sequencing
[Wed Jun 20 17:18:44 2018] [error] [client 10.15.60.49] warnings.warn('There are known rendering problems with Cairo <= 1.14.0'), referer: http://flavia.isciii.es/drylab/service_request_internal_sequencing
[Wed Jun 20 17:18:45 2018] [error] [client 10.15.60.49] /srv/iSkyLIMS/virtualenv/lib/python3.6/site-packages/weasyprint/fonts.py:43: UserWarning: @font-face support needs Pango >= 1.38, referer: http://flavia.isciii.es/drylab/service_request_internal_sequencing
[Wed Jun 20 17:18:45 2018] [error] [client 10.15.60.49] warnings.warn('@font-face support needs Pango >= 1.38'), referer: http://flavia.isciii.es/drylab/service_request_internal_sequencing
[Wed Jun 20 17:18:46 2018] [error] [client 10.15.60.49] File does not exist: /srv/iSkyLIMS/static/iSkyLIMS_common_static/vendor/swiper/js/maps

[saramonzon]

Problem related with centos 6.9 cairo lib version (1.8.8). Probably Centos 7 is needed for this. Pending for next version of iSkyLIMS.