Fix an assertion in SkipPatternJarScanner

Closes gh-8153

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/SkipPatternJarScanner.java

@@ -50,7 +50,7 @@ class SkipPatternJarScanner extends StandardJarScanner {
 
 	SkipPatternJarScanner(JarScanner jarScanner, Set<String> patterns) {
 		Assert.notNull(jarScanner, "JarScanner must not be null");
-		Assert.notNull(jarScanner, "Patterns must not be null");
+		Assert.notNull(patterns, "Patterns must not be null");
 		this.jarScanner = jarScanner;
 		this.patterns = patterns;
 		setPatternToTomcat8SkipFilter();