Consolidate error handling retry logic

src/sliding-sync.ts

@@ -846,18 +846,16 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                         currentPos = undefined;
                         await sleep(50); // in case the 400 was for something else; don't tightloop
                         continue;
-                    }
+                    } // else fallthrough to generic error handling
-                    await sleep(5000);
                 } else if (this.needsResend || err === "aborted") {
                     // don't sleep as we caused this error by abort()ing the request.
                     // we check for 'aborted' because that's the error Jest returns and without it
                     // we get warnings about not exiting fast enough.
                     continue;
-                } else {
+                }
                 logger.error(err);
                 await sleep(5000);
             }
-            }
             if (!resp) {
                 continue;
             }