Restore origin behaivour of evaluateToString()

Author: LEDfan

src/main/java/eu/openanalytics/containerproxy/spec/expression/SpecExpressionResolver.java

@@ -112,11 +112,12 @@ public <T> T evaluate(String expression, SpecExpressionContext context, Class<T>
 	}
 
 	public String evaluateToString(String expression, SpecExpressionContext context) {
-		String res = evaluate(expression, context, String.class);
+		// use the toString() method and not the conversionService in order to maintain behaviour of ShinyProxy 2.6.1 and earlier
+		Object res = evaluate(expression, context, Object.class);
 		if (res == null) {
 			return "";
 		}
-		return res;
+		return res.toString();
 	}
 
 	public Long evaluateToLong(String expression, SpecExpressionContext context) {

src/main/java/eu/openanalytics/containerproxy/spec/expression/SpelField.java

@@ -244,7 +244,6 @@ public SpelField.StringList resolve(SpecExpressionResolver specExpressionResolve
             if (originalValue == null) {
                 return new SpelField.StringList(null, null);
             }
-            // TODO implementation is different from ExpressionAwareContainerSpec::resolve
             return new SpelField.StringList(originalValue, specExpressionResolver.evaluateToList(originalValue, specExpressionContext));
         }