relays: strip trailing / from relay urls

Fixes: https://github.com/damus-io/damus/issues/1443
Changelog-Fixed: Fix issue with slashes on relay urls causing relay connection problems

damusTests/UrlTests.swift

@@ -0,0 +1,28 @@
+//
+//  UrlTests.swift
+//  damusTests
+//
+//  Created by William Casarin on 2023-08-06.
+//
+
+import XCTest
+@testable import damus
+
+final class UrlTests: XCTestCase {
+
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+
+    func testRelayUrlStripsEndingSlash() throws {
+        let url1 = RelayURL("wss://jb55.com/")!
+        let url2 = RelayURL("wss://jb55.com")!
+        XCTAssertEqual(url1, url2)
+        XCTAssertEqual(url1.url.absoluteString, "wss://jb55.com")
+    }
+
+}