ScriptModule: make context class loader non-null

Groovy assumes it will be non-null, and crashes if it's null.

When is it null? Not totally clear. But it can happen! See its javadoc.

Author: ctrueden

src/main/java/org/scijava/script/ScriptModule.java

@@ -123,6 +123,13 @@ public ScriptInfo getInfo() {
 
 	@Override
 	public void run() {
+		// HACK: Work around code (Groovy!) assuming
+		// context class loader can't be null.
+		final ClassLoader cl = Thread.currentThread().getContextClassLoader();
+		if (cl == null) {
+			Thread.currentThread().setContextClassLoader(Context.getClassLoader());
+		}
+
 		final ScriptEngine engine = getEngine();
 		final String path = getInfo().getPath();