Improve error message when no resources exist at a script location

See gh-25620

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceInitializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -161,7 +161,7 @@ class DataSourceInitializer {
 				}
 				else if (validate) {
 					throw new InvalidConfigurationPropertyValueException(propertyName, resource,
-							"The specified resource does not exist.");
+							"Resource '" + location + "' does not exist.");
 				}
 			}
 		}