fix: keys sign_as_user header

Author: Bilb

include/session/config/groups/keys.hpp

@@ -491,7 +491,7 @@ class Keys : public ConfigSig {
             std::span<const unsigned char> signing_value,
             bool binary = false) const;
 
-    static Keys::swarm_auth swarm_subaccount_sign_as_user(
+    static swarm_auth swarm_subaccount_sign_as_user(
             std::span<const unsigned char> user_ed25519_sk,
             std::span<const unsigned char> msg,
             std::span<const unsigned char> sign_val,

src/config/groups/keys.cpp

@@ -779,7 +779,8 @@ Keys::swarm_auth Keys::swarm_subaccount_sign(
         std::span<const unsigned char> sign_val,
         bool binary) const {
     auto user_ed25519_sk_buf = this->user_ed25519_sk.data();
-    return Keys::swarm_subaccount_sign_as_user(user_ed25519_sk_buf, msg, sign_val, binary);
+
+    return Keys::swarm_subaccount_sign_as_user(to_span(user_ed25519_sk_buf), msg, sign_val, binary);
 }
 
 bool Keys::swarm_verify_subaccount(