message: [move prover] fix signer type
  Closes:
  Approved by: wrwg
diff: @@ -3045,8 +3045,7 @@ impl<'env, 'translator, 'module_translator> ExpTranslator<'env, 'translator, 'mo
  match &type_name.value {
  Builtin(builtin_type_name) => match &builtin_type_name.value {
  Address => Type::new_prim(PrimitiveType::Address),
  - // TODO fix this for a real signer type
  - Signer => Type::new_prim(PrimitiveType::Address),
  + Signer => Type::new_prim(PrimitiveType::Signer),
  U8 => Type::new_prim(PrimitiveType::U8),
  U64 => Type::new_prim(PrimitiveType::U64),
  U128 => Type::new_prim(PrimitiveType::U128),
  