Cleans:
• poppler_viewer.c:827:3: warning: enumeration value
'POPPLER_ACTION_NONE' not handled in switch
• poppler_viewer.c:827:3: warning: enumeration value
'POPPLER_ACTION_RENDITION' not handled in switch
• poppler_viewer.c:827:3: warning: enumeration value
'POPPLER_ACTION_OCG_STATE' not handled in switch
• poppler_viewer.c:827:3: warning: enumeration value
'POPPLER_ACTION_JAVASCRIPT' not handled in switch