Drop Python 3.3 support from several stubs (#2265)

* Drop Python 3.3 support from several stubs

* Revert wrong socketserver changes

stdlib/3/collections/__init__.pyi

@@ -329,20 +329,19 @@ class defaultdict(Dict[_KT, _VT], Generic[_KT, _VT]):
     # TODO __reversed__
     def copy(self: _DefaultDictT) -> _DefaultDictT: ...
 
-if sys.version_info >= (3, 3):
-    class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
-        def __init__(self, *maps: Mapping[_KT, _VT]) -> None: ...
+class ChainMap(MutableMapping[_KT, _VT], Generic[_KT, _VT]):
+    def __init__(self, *maps: Mapping[_KT, _VT]) -> None: ...
 
-        @property
-        def maps(self) -> List[Mapping[_KT, _VT]]: ...
+    @property
+    def maps(self) -> List[Mapping[_KT, _VT]]: ...
 
-        def new_child(self, m: Mapping[_KT, _VT] = ...) -> typing.ChainMap[_KT, _VT]: ...
+    def new_child(self, m: Mapping[_KT, _VT] = ...) -> typing.ChainMap[_KT, _VT]: ...
 
-        @property
-        def parents(self) -> typing.ChainMap[_KT, _VT]: ...
+    @property
+    def parents(self) -> typing.ChainMap[_KT, _VT]: ...
 
-        def __setitem__(self, k: _KT, v: _VT) -> None: ...
-        def __delitem__(self, v: _KT) -> None: ...
-        def __getitem__(self, k: _KT) -> _VT: ...
-        def __iter__(self) -> Iterator[_KT]: ...
-        def __len__(self) -> int: ...
+    def __setitem__(self, k: _KT, v: _VT) -> None: ...
+    def __delitem__(self, v: _KT) -> None: ...
+    def __getitem__(self, k: _KT) -> _VT: ...
+    def __iter__(self) -> Iterator[_KT]: ...
+    def __len__(self) -> int: ...

stdlib/3/collections/abc.pyi

@@ -3,25 +3,24 @@
 # https://docs.python.org/3.3/whatsnew/3.3.html#collections
 import sys
 
-if sys.version_info >= (3, 3):
-    from . import (
-        Container as Container,
-        Hashable as Hashable,
-        Iterable as Iterable,
-        Iterator as Iterator,
-        Sized as Sized,
-        Callable as Callable,
-        Mapping as Mapping,
-        MutableMapping as MutableMapping,
-        Sequence as Sequence,
-        MutableSequence as MutableSequence,
-        Set as Set,
-        MutableSet as MutableSet,
-        MappingView as MappingView,
-        ItemsView as ItemsView,
-        KeysView as KeysView,
-        ValuesView as ValuesView,
-    )
+from . import (
+    Container as Container,
+    Hashable as Hashable,
+    Iterable as Iterable,
+    Iterator as Iterator,
+    Sized as Sized,
+    Callable as Callable,
+    Mapping as Mapping,
+    MutableMapping as MutableMapping,
+    Sequence as Sequence,
+    MutableSequence as MutableSequence,
+    Set as Set,
+    MutableSet as MutableSet,
+    MappingView as MappingView,
+    ItemsView as ItemsView,
+    KeysView as KeysView,
+    ValuesView as ValuesView,
+)
 
 if sys.version_info >= (3, 5):
     from . import (