fixed bug in recursion detection (not really a fix, I don't understand why this happens only in python3)

jedi/helpers.py

@@ -36,7 +36,10 @@ class RecursionDecorator(object):
         return False
 
     def pop_stmt(self):
-        self.current = self.current.parent
+        if self.current is not None:
+            # I don't know how current can be None, but sometimes it happens
+            # with Python3.
+            self.current = self.current.parent
 
     def _check_recursion(self):
         test = self.current

jedi/imports.py

@@ -141,6 +141,7 @@ class ImportPath(object):
                 scope, rest = self._follow_file_system()
             except ModuleNotFound:
                 debug.warning('Module not found: ' + str(self.import_stmt))
+                evaluate.follow_statement.pop_stmt()
                 return []
 
             scopes = [scope]

test/regression.py

@@ -10,6 +10,7 @@ sys.path.append('.')
 
 from _compatibility import is_py25
 import api
+
 #api.set_debug_function(api.debug.print_to_stdout)