fix broken link from horovod doc (#2186)

Co-authored-by: Desroziers <sylvain.desroziers@ifpen.fr>

Author: sdesrozis

ignite/distributed/utils.py

@@ -518,7 +518,7 @@ def train_fn(local_rank, a, b, c):
             - | "horovod" : comm(=None), more info: `hvd_init`_.
 
     .. _torch_init: https://pytorch.org/docs/stable/distributed.html#torch.distributed.init_process_group
-    .. _hvd_init: https://horovod.readthedocs.io/en/latest/api.html#horovod.torch.init
+    .. _hvd_init: https://horovod.readthedocs.io/en/latest/api.html#module-horovod.torch
 
     .. versionchanged:: 0.4.2
         ``backend`` now accepts `horovod` distributed framework.