Fix comic reader arrow visiblilty for one paged comic files

Changed logging during kobo sync

cps/kobo.py

@@ -315,7 +315,7 @@ def generate_sync_response(sync_token, sync_results, set_cont=False):
             extra_headers["x-kobo-recent-reads"] = store_response.headers.get("x-kobo-recent-reads")
 
         except Exception as ex:
-            log.error("Failed to receive or parse response from Kobo's sync endpoint: {}".format(ex))
+            log.error_or_exception("Failed to receive or parse response from Kobo's sync endpoint: {}".format(ex))
     if set_cont:
         extra_headers["x-kobo-sync"] = "continue"
     sync_token.to_headers(extra_headers)

cps/static/js/kthoom.js

@@ -179,26 +179,23 @@ kthoom.ImageFile = function(file) {
 };
 
 function updateDirectionButtons(){
-    $("#right").show();
-    $("#left").show();
+    var left, right = 1;
     if (currentImage == 0 ) {
         if (settings.direction === 0) {
-            $("#right").show();
-            $("#left").hide();
+            left = 0;
         } else {
-            $("#left").show();
-            $("#right").hide();
+            right = 0;
         }
     }
     if ((currentImage + 1) >= Math.max(totalImages, imageFiles.length)) {
         if (settings.direction === 0) {
-            $("#left").show();
-            $("#right").hide();
+            right = 0;
         } else {
-            $("#right").show();
-            $("#left").hide();
-        }
+            left = 0;
+       }
     }
+    left === 1 ? $("#left").show() : $("#left").hide();
+    right === 1 ? $("#right").show() : $("#right").hide();
 }
 function initProgressClick() {
     $("#progress").click(function(e) {