SEC-2878: Clean imports in UsernamePasswordAuthenticationFilter

web/src/main/java/org/springframework/security/web/authentication/UsernamePasswordAuthenticationFilter.java

@@ -16,18 +16,16 @@
 package org.springframework.security.web.authentication;
 
 
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-import javax.servlet.http.HttpSession;
-
 import org.springframework.security.authentication.AuthenticationServiceException;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.AuthenticationException;
-import org.springframework.security.web.util.TextEscapeUtils;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
 import org.springframework.util.Assert;
 
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
 
 /**
  * Processes an authentication form submission. Called {@code AuthenticationProcessingFilter} prior to Spring Security