Fix race condition by not caching AstNodes when using eager execution

Author: jasmith-hs

src/main/java/com/hubspot/jinjava/Jinjava.java

@@ -97,7 +97,7 @@ public Jinjava(JinjavaConfig globalConfig) {
       TreeBuilder.class.getName(),
       EagerExtendedSyntaxBuilder.class.getName()
     );
-    //    eagerExpConfig.setProperty(ExpressionFactoryImpl.PROP_CACHE_SIZE, "0");
+    eagerExpConfig.setProperty(ExpressionFactoryImpl.PROP_CACHE_SIZE, "0");
 
     TypeConverter converter = new TruthyTypeConverter();
     this.expressionFactory = new ExpressionFactoryImpl(expConfig, converter);