Don't attempt to resolve hostname for git init

During initialization JGit may attempt to resolve hostname. On some
systems this can take more than desired triggering timeouts.
This change does two things:
- sets the default committer for changes, lack of which probably
  triggered the check
- sets the default hostname to `localhost` (we don't care), in case
  something else in JGit still wants to resolve hostname

Closes #6447.

engine/language-server/src/main/scala/org/enso/languageserver/vcsmanager/EmptyUserConfigReader.scala

@@ -18,7 +18,7 @@ final class EmptyUserConfigReader extends SystemReader {
 
   /** @inheritdoc */
   override def getHostname: String =
-    proxy.getHostname
+    "localhost"
 
   /** @inheritdoc */
   override def getenv(variable: String): String = {

engine/language-server/src/main/scala/org/enso/languageserver/vcsmanager/Git.scala

@@ -113,6 +113,7 @@ private class Git(ensoDataDirectory: Option[Path], asyncInit: Boolean)
         .setAll(true)
         .setMessage("Initial commit")
         .setAuthor(AuthorName, AuthorEmail)
+        .setCommitter(AuthorName, AuthorEmail)
         .setNoVerify(true)
         .call()
       ()
@@ -166,6 +167,7 @@ private class Git(ensoDataDirectory: Option[Path], asyncInit: Boolean)
         .commit()
         .setMessage(commitName)
         .setAuthor(AuthorName, AuthorEmail)
+        .setCommitter(AuthorName, AuthorEmail)
         .call()
       RepoCommit(revCommit.getName(), revCommit.getShortMessage())
     }.mapError(errorHandling)

engine/language-server/src/test/scala/org/enso/languageserver/websocket/json/VcsManagerTest.scala

@@ -1461,6 +1461,7 @@ class VcsManagerTest extends BaseServerTest with RetrySpec with FlakySpec {
       .setAll(true)
       .setMessage("Initial commit")
       .setAuthor("Enso VCS", "vcs@enso.io")
+      .setCommitter("Enso VCS", "vcs@enso.io")
       .call()
     test(client)
   }
@@ -1491,7 +1492,11 @@ class VcsManagerTest extends BaseServerTest with RetrySpec with FlakySpec {
 
   def commit(root: File, msg: String): RevCommit = {
     val jgit = new JGit(repository(root.toPath))
-    jgit.commit.setMessage(msg).setAuthor("Enso VCS", "vcs@enso.io").call()
+    jgit.commit
+      .setMessage(msg)
+      .setAuthor("Enso VCS", "vcs@enso.io")
+      .setCommitter("Enso VCS", "vcs@enso.io")
+      .call()
   }
 
   def add(root: File, paths: Path*): Boolean = {