sync: Safely skip already deleted projects

Do not error if a project is missing on the filesystem, is deleted
from manifest.xml, but still exists in project.list.

Change-Id: I1d13e435473c83091e27e4df571504ef493282dd

subcmds/sync.py

@@ -147,6 +147,9 @@ later is required to fix a server side protocol bug.
         if not path:
           continue
         if path not in new_project_paths:
+          """If the path has already been deleted, we don't need to do it
+          """
+          if os.path.exists(self.manifest.topdir + '/' + path):
               project = Project(
                              manifest = self.manifest,
                              name = path,
@@ -157,6 +160,7 @@ later is required to fix a server side protocol bug.
                              relpath = path,
                              revisionExpr = 'HEAD',
                              revisionId = None)
+
               if project.IsDirty():
                 print >>sys.stderr, 'error: Cannot remove project "%s": \
 uncommitted changes are present' % project.relpath