Hi piwik folks.
After a fresh installation i got a error message on the top of the login screen. This error appears only once. If i refresh the login page the message has gone. I use piwik version 1.10.1
Notice: Undefined variable: header in /usr/share/piwik/core/Http.php on line 527
Backtrace -->
#0 Piwik_ErrorHandler(...) called at [/usr/share/piwik/core/Http.php:527]
#1 Piwik_Http::sendHttpRequestBy(...) called at [/usr/share/piwik/core/Http.php:79]
#2 Piwik_Http::sendHttpRequest(...) called at [/usr/share/piwik/core/UpdateCheck.php:64]
#3 Piwik_UpdateCheck::check(...) called at [/usr/share/piwik/plugins/CoreUpdater/CoreUpdater.php:88]
#4 Piwik_CoreUpdater->updateCheck(...) called at [:]
#5 call_user_func_array(...) called at [/usr/share/piwik/libs/Event/Dispatcher.php:284]
#6 Event_Dispatcher->postNotification(...) called at [/usr/share/piwik/core/PluginsManager.php:723]
#7 Piwik_PostEvent(...) called at [/usr/share/piwik/core/FrontController.php:322]
#8 Piwik_FrontController->init(...) called at [/usr/share/piwik/index.php:52]
Any suggestions?