simplify "is_admin" as the flag was added back for administrators

GitLab/API.pm

@@ -77,6 +77,8 @@ sub new {
     croak "GitLab authentication failed: ", $response->message
         unless $response->is_success;
 
+    $self->{session} = $user    unless defined $self->{session};
+
     my $version = $self->version(-immortal => 1);
 
     my $vn = defined $version
@@ -113,21 +115,7 @@ sub die_on_error {
 }
 
 sub is_admin {
-    my ($self) = @_;
-
-    return $self->{is_admin} if $self->{is_admin};
-    my $sudo = $self->{impersonate};
-    $self->{is_admin} = 1;
-
-    $self->sudo(undef);
-    $self->{session} = $self->whoami
-        unless defined $self->{session};
-
-    $self->sudo($self->{session}->{username});
-    my ($user, $response) = $self->whoami(-response => 1, -immortal => 1);
-    $self->sudo($sudo);
-
-    return $self->{session}->{is_admin} = $response->is_success;
+    return $_[0]->{session}->{is_admin};
 }
 
 #===============================================================================
@@ -153,7 +141,6 @@ sub login {
     if ($response->is_success) {
         $log->debug("login successful");
         $self->{session}    = $self->json->decode($response->decoded_content);
-        $self->{is_admin}   = $self->{session}->{is_admin};
         $self->{token}      = $self->{session}->{private_token};
     } else {
         $log->fatal("login failed: " . $response->status_line);