Fix server error 500 when user is logged out
Fix server error 500 when user is logged out

f98ebaaf moved the passive_logon code to a new function from
api/__init__.py to util/flask.py.  Before that move any fallthrough
would hit return NO_CONTENT, but now it returns nothing which makes
flask complain.

senttech/OctoPrint,leductan-nguyen/RaionPi,masterhou/OctoPrint,Mikk36/OctoPrint,EZ3-India/EZ-Remote,Jaesin/OctoPrint,jneves/OctoPrint,EZ3-India/EZ-Remote,alex1818/OctoPrint,nicanor-romero/OctoPrint,dragondgold/OctoPrint,mcanes/OctoPrint,punkkeks/OctoPrint,markwal/OctoPrint,alex1818/OctoPrint,bicephale/OctoPrint,javivi001/OctoPrint,eddieparker/OctoPrint,SeveQ/OctoPrint,MoonshineSG/OctoPrint,beeverycreative/BEEweb,ErikDeBruijn/OctoPrint,beeverycreative/BEEweb,nicanor-romero/OctoPrint,spapadim/OctoPrint,MoonshineSG/OctoPrint,bicephale/OctoPrint,shaggythesheep/OctoPrint,EZ3-India/EZ-Remote,JackGavin13/octoprint-test-not-finished,ryanneufeld/OctoPrint,javivi001/OctoPrint,markwal/OctoPrint,eddieparker/OctoPrint,Jaesin/OctoPrint,dragondgold/OctoPrint,Salandora/OctoPrint,nickverschoor/OctoPrint,SeveQ/OctoPrint,leductan-nguyen/RaionPi,Voxel8/OctoPrint,CapnBry/OctoPrint,shohei/Octoprint,CapnBry/OctoPrint,shohei/Octoprint,punkkeks/OctoPrint,MoonshineSG/OctoPrint,Salandora/OctoPrint,sstocker46/OctoPrint,jneves/OctoPrint,eliasbakken/OctoPrint,JackGavin13/octoprint-test-not-finished,Voxel8/OctoPrint,chriskoz/OctoPrint,Voxel8/OctoPrint,Javierma/OctoPrint-TFG,uuv/OctoPrint,MaxOLydian/OctoPrint,eliasbakken/OctoPrint,CapnBry/OctoPrint,foosel/OctoPrint,leductan-nguyen/RaionPi,mcanes/OctoPrint,foosel/OctoPrint,masterhou/OctoPrint,Jaesin/OctoPrint,Salandora/OctoPrint,CapnBry/OctoPrint,Javierma/OctoPrint-TFG,spapadim/OctoPrint,uuv/OctoPrint,shohei/Octoprint,MaxOLydian/OctoPrint,ErikDeBruijn/OctoPrint,Salandora/OctoPrint,mrbeam/OctoPrint,ryanneufeld/OctoPrint,beeverycreative/BEEweb,MaxOLydian/OctoPrint,alex1818/OctoPrint,JackGavin13/octoprint-test-not-finished,eliasbakken/OctoPrint,Javierma/OctoPrint-TFG,shohei/Octoprint,mrbeam/OctoPrint,beeverycreative/BEEweb,jneves/OctoPrint,foosel/OctoPrint,chriskoz/OctoPrint,SeveQ/OctoPrint,shohei/Octoprint,markwal/OctoPrint,dragondgold/OctoPrint,dansantee/OctoPrint,dansantee/OctoPrint,spapadim/OctoPrint,Skeen/OctoPrint,Jaesin/OctoPrint,mayoff/OctoPrint,Javierma/OctoPrint-TFG,chriskoz/OctoPrint,masterhou/OctoPrint,nickverschoor/OctoPrint,nickverschoor/OctoPrint,mayoff/OctoPrint,senttech/OctoPrint,ryanneufeld/OctoPrint,bicephale/OctoPrint,mrbeam/OctoPrint,sstocker46/OctoPrint,Mikk36/OctoPrint,leductan-nguyen/RaionPi,dansantee/OctoPrint,sstocker46/OctoPrint,foosel/OctoPrint,javivi001/OctoPrint,Mikk36/OctoPrint,chriskoz/OctoPrint,bicephale/OctoPrint,Skeen/OctoPrint,nickverschoor/OctoPrint,senttech/OctoPrint,nicanor-romero/OctoPrint,shaggythesheep/OctoPrint,ryanneufeld/OctoPrint,ErikDeBruijn/OctoPrint,punkkeks/OctoPrint,JackGavin13/octoprint-test-not-finished,MoonshineSG/OctoPrint,mayoff/OctoPrint,EZ3-India/EZ-Remote,shaggythesheep/OctoPrint,Skeen/OctoPrint,senttech/OctoPrint,eddieparker/OctoPrint,uuv/OctoPrint,mcanes/OctoPrint