Update cosmos-sdk checkout to 0.50.4

This brings cosmos protos up to date with tendermint 0.38, which is the version included by the proto files from the ibc-go checkout.

src/COSMOS_SDK_COMMIT

@@ -1 +1 @@
-2e9e5d6eea24d6c11eddc9c002c66e89ae036187
+7dbed2fc0c3ed7c285645e21cb1037d8810372ae

src/prost/cosmos.app.v1alpha1.rs

@@ -51,7 +51,7 @@ pub struct PackageReference {
     ///
     /// When a new version of a module is released and items are added to existing
     /// .proto files, these definitions should contain comments of the form
-    /// "Since Revision N" where N is an integer revision.
+    /// "Since: Revision N" where N is an integer revision.
     ///
     /// When the module runtime starts up, it will check the pinned proto
     /// image and panic if there are runtime protobuf definitions that are not

src/prost/cosmos.bank.module.v1.rs

@@ -2,8 +2,8 @@
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
 pub struct Module {
-    /// blocked_module_accounts configures exceptional module accounts which should be blocked from receiving funds.
-    /// If left empty it defaults to the list of account names supplied in the auth module configuration as
+    /// blocked_module_accounts_override configures exceptional module accounts which should be blocked from receiving
+    /// funds. If left empty it defaults to the list of account names supplied in the auth module configuration as
     /// module_account_permissions
     #[prost(string, repeated, tag = "1")]
     pub blocked_module_accounts_override: ::prost::alloc::vec::Vec<