fix: configuration of cors

Refs: #430

src/main/java/ca/uhn/fhir/jpa/starter/annotations/OnCorsPresent.java

@@ -0,0 +1,18 @@
+package ca.uhn.fhir.jpa.starter.annotations;
+
+import ca.uhn.fhir.jpa.starter.AppProperties;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.context.annotation.Condition;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+
+public class OnCorsPresent implements Condition {
+	@Override
+	public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata metadata) {
+
+		AppProperties config = Binder.get(conditionContext.getEnvironment()).bind("hapi.fhir", AppProperties.class).orElse(null);
+		if (config == null) return false;
+		if (config.getCors() == null) return false;
+		return true;
+	}
+}