Malicious Code Scanner Fix

On the latest release the code scanner isn't functioning, this should allow it to work as normal again

Author: Konloch

src/main/java/the/bytecode/club/bytecodeviewer/decompilers/bytecode/InstructionPrinter.java

@@ -76,6 +76,9 @@ public InstructionPrinter(MethodNode m, InstructionPattern pattern, TypeAndName[
   }
 
   private void precalculateLabelIndexes(MethodNode m) {
+    if(m == null)
+      return;
+    
     int lIdx = 0;
     for (AbstractInsnNode ain : m.instructions) {
       if (ain.getType() == AbstractInsnNode.LABEL) {