[#629] go.mod/protobuf: Bump version

- google.golang.org/protobuf v1.25.0 => v1.26.0
- github.com/golang/protobuf v1.4.3 => v1.5.2

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

go.mod

@@ -3,7 +3,7 @@ module github.com/nspcc-dev/neofs-node
 go 1.14
 
 require (
-	github.com/golang/protobuf v1.4.3
+	github.com/golang/protobuf v1.5.2
 	github.com/google/uuid v1.1.1
 	github.com/hashicorp/golang-lru v0.5.4
 	github.com/klauspost/compress v1.11.3
@@ -32,7 +32,7 @@ require (
 	golang.org/x/net v0.0.0-20191105084925-a882066a44e0 // indirect
 	golang.org/x/tools v0.0.0-20200123022218-593de606220b // indirect
 	google.golang.org/grpc v1.29.1
-	google.golang.org/protobuf v1.25.0
+	google.golang.org/protobuf v1.26.0
 )
 
 // Used for debug reasons