Fix sub parse bug

Was accidentally consuming one more byte than I was expecting when reaching the end of the second term.
This was causing the parser to work properly in the case that a queue group was specified, but failing and consuming the next message (usually a PING) as the SID.

src/server/message_parser.zig

@@ -260,9 +260,10 @@ pub const Message = union(MessageType) {
                     } else |err| return err;
 
                     var acc: std.ArrayList(u8) = try .initCapacity(alloc, 32);
-                    while (in.takeByte()) |byte| {
+                    while (in.peekByte()) |byte| {
                         if (std.ascii.isWhitespace(byte)) break;
                         try acc.append(alloc, byte);
+                        in.toss(1);
                     } else |err| return err;
 
                     break :blk try acc.toOwnedSlice(alloc);