GUAC-872: Fix keysym definition for PageUp/PageDown key identifiers.

guacamole-common-js/src/main/webapp/modules/Keyboard.js

@@ -467,8 +467,8 @@ Guacamole.Keyboard = function(element) {
         "Meta": [0xFFE7, 0xFFE7, 0xFFE8],
         "ModeChange": [0xFF7E],
         "NumLock": [0xFF7F],
-        "PageDown": [0xFF55],
-        "PageUp": [0xFF56],
+        "PageDown": [0xFF56],
+        "PageUp": [0xFF55],
         "Pause": [0xFF13],
         "Play": [0xFD16],
         "PreviousCandidate": [0xFF3E],