fixed a bug in updateprojectfile.
fixed a bug in updateprojectfile.

the project file format migration from revision 7 to revision 8 would fail.

glebmish/appleseed,Vertexwahn/appleseed,gospodnetic/appleseed,est77/appleseed,aiivashchenko/appleseed,luisbarrancos/appleseed,docwhite/appleseed,glebmish/appleseed,Vertexwahn/appleseed,glebmish/appleseed,docwhite/appleseed,glebmish/appleseed,pjessesco/appleseed,Aakash1312/appleseed,pjessesco/appleseed,Vertexwahn/appleseed,luisbarrancos/appleseed,est77/appleseed,Biart95/appleseed,Biart95/appleseed,appleseedhq/appleseed,Vertexwahn/appleseed,Aakash1312/appleseed,appleseedhq/appleseed,est77/appleseed,dictoon/appleseed,luisbarrancos/appleseed,Biart95/appleseed,glebmish/appleseed,Aakash1312/appleseed,docwhite/appleseed,Biart95/appleseed,est77/appleseed,pjessesco/appleseed,est77/appleseed,dictoon/appleseed,dictoon/appleseed,docwhite/appleseed,aytekaman/appleseed,luisbarrancos/appleseed,dictoon/appleseed,dictoon/appleseed,Aakash1312/appleseed,appleseedhq/appleseed,appleseedhq/appleseed,aytekaman/appleseed,aiivashchenko/appleseed,gospodnetic/appleseed,pjessesco/appleseed,aiivashchenko/appleseed,appleseedhq/appleseed,luisbarrancos/appleseed,aiivashchenko/appleseed,Biart95/appleseed,gospodnetic/appleseed,aiivashchenko/appleseed,pjessesco/appleseed,Vertexwahn/appleseed,docwhite/appleseed,aytekaman/appleseed,Aakash1312/appleseed,aytekaman/appleseed,gospodnetic/appleseed,gospodnetic/appleseed,aytekaman/appleseed