fix link to the assignment's github page on the assignment detail and the build report

Author: palves-ulht

src/main/kotlin/org/dropProject/dao/Assignment.kt

@@ -209,8 +209,8 @@ data class Assignment(
 
         val parts = gitRepositoryUrl.split(":")
         val hostAndPath = parts[1].removeSuffix(".git").split("/")
-        val username = parts[0].substringAfter("@")
-        val host = hostAndPath[0]
+        val host = parts[0].substringAfter("@")
+        val username = hostAndPath[0]
         val repositoryName = hostAndPath[1]
 
         return "https://$host/$username/$repositoryName"