Ensure file from watched folder is stable in size before upload
Ensure file from watched folder is stable in size before upload

Additional fix for #1760

foosel/OctoPrint,foosel/OctoPrint,Salandora/OctoPrint,beeverycreative/BEEweb,Jaesin/OctoPrint,bicephale/OctoPrint,Jaesin/OctoPrint,JackGavin13/octoprint-test-not-finished,JackGavin13/octoprint-test-not-finished,Jaesin/OctoPrint,beeverycreative/BEEweb,JackGavin13/octoprint-test-not-finished,beeverycreative/BEEweb,foosel/OctoPrint,bicephale/OctoPrint,Salandora/OctoPrint,JackGavin13/octoprint-test-not-finished,foosel/OctoPrint,bicephale/OctoPrint,Salandora/OctoPrint,Salandora/OctoPrint,bicephale/OctoPrint,Jaesin/OctoPrint,beeverycreative/BEEweb