[K/N] Remove remains of jcenter from kotlin-native/

Revert two special entries

Use proper mavenCentral()

Remove remains of jcenter from kotlin-native/

Merge-request: KT-MR-7610
Merged-by: Vladimir Sukharev <Vladimir.Sukharev@jetbrains.com>

kotlin-native/performance/KotlinVsSwift/build.gradle

@@ -1,9 +1,7 @@
 buildscript {
     apply from: "$rootProject.projectDir/../gradle/kotlinGradlePlugin.gradle"
     repositories {
-        maven {
-            url 'https://cache-redirector.jetbrains.com/jcenter'
-        }
+        mavenCentral()
     }
 }