Properly URL encode credentials on Subsonic

Previous commit (8ec4551) has been reverted, as it has encoded even equal signs (=), and and signs (&), which should not have been encoded. Nextcloud Music has subsequently failed to receive separate username and password and has therefore failed whilst authenticating the user.

Example of URL beforehand:
https://cloud.example.com/index.php/apps/music/subsonic/rest/stream.view?id=track-4936&v=1.13.0&c=feishin_&u%3Dtest-test%40example.com%26p%3Dpassword

Example of URL now:
https://cloud.example.com/index.php/apps/music/subsonic/rest/stream.view?id=track-4936&v=1.13.0&c=feishin_&u=test-test%40example.com&p=password

src/renderer/api/subsonic/subsonic-controller.ts

@@ -65,15 +65,15 @@ export const SubsonicController: ControllerEndpoint = {
         const cleanServerUrl = `${url.replace(/\/$/, '')}/rest`;
 
         if (body.legacy) {
-            credential = `u=${body.username}&p=${body.password}`;
+            credential = `u=${encodeURIComponent(body.username)}&p=${encodeURIComponent(body.password)}`;
             credentialParams = {
                 p: body.password,
                 u: body.username,
             };
         } else {
             const salt = randomString(12);
             const hash = md5(body.password + salt);
-            credential = `u=${body.username}&s=${salt}&t=${hash}`;
+            credential = `u=${encodeURIComponent(body.username)}&s=${encodeURIComponent(salt)}&t=${encodeURIComponent(hash)}`;
             credentialParams = {
                 s: salt,
                 t: hash,