fix: check for correct URI pattern (#1732)

Signed-off-by: achmelo <a.chmelo@gmail.com>

Author: achmelo

gateway-service/src/main/java/org/zowe/apiml/gateway/filters/pre/PerServiceGZipFilter.java

@@ -85,7 +85,13 @@ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse
     private boolean requiresCompression(HttpServletRequest request) {
         String[] uriParts = request.getRequestURI().split("/");
         List<ServiceInstance> instances;
+        if (uriParts.length < 2) {
+            return false;
+        }
         if ("api".equals(uriParts[1]) || "ui".equals(uriParts[1])) {
+            if (uriParts.length < 4) {
+                return false;
+            }
             instances = discoveryClient.getInstances(uriParts[3]);
         } else {
             instances = discoveryClient.getInstances(uriParts[1]);