add missing case for opcode decoding

Author: Ruzihm

OpenDreamRuntime/Procs/ProcDecoder.cs

@@ -142,6 +142,8 @@ public ITuple DecodeInstruction() {
             case DreamProcOpcode.Gradient:
             case DreamProcOpcode.Rgb:
                 return (opcode, (DMCallArgumentsType)ReadByte(), ReadInt());
+            case DreamProcOpcode.Animate:
+                return (opcode, (DMCallArgumentsType)ReadByte(), ReadInt());
 
             case DreamProcOpcode.Call:
                 return (opcode, ReadReference(), (DMCallArgumentsType)ReadByte(), ReadInt());