fix(rpc): prevent division by zero in deserialize_tensor (#20712)

fix(rpc): prevent division by zero in deserialize_tensor (#20712)

rpc : prevent division by zero in deserialize_tensor

When receiving an RPC message with a deprecated tensor type (e.g., type 4 or 5 where `blck_size == 0`), `ggml_row_size()` will trigger a division by zero (SIGFPE) and crash the rpc-server.

This patch adds a simple validation check in `deserialize_tensor` to return `nullptr` if the requested tensor type has a block size of 0.

(Note: This was originally reported via Security Advisory and maintainer suggested dropping a patch here).

* style: remove trailing whitespace