Upgrade to Tomcat 9.0.50 (#66)

Author: labkey-adam

standalone/gradle.properties

@@ -11,7 +11,7 @@ gradlePluginsVersion=1.28.0
 labkeyClientApiVersion=1.3.2
 
 # used by the LabKey Jsp Gradle plugin for declaring dependencies
-apacheTomcatVersion=8.5.51
+apacheTomcatVersion=9.0.50
 servletApiVersion=3.0
 
 # Example external dependency used in build file