[taskmgr] improvement german: too long string in statusbar

ros displays a little more information than windows in taskmgr status bar for memory usage which is good.
However this leads to a cut off string in german when you do not resize the taskmgr in x.
Therefore my propose is to shorten the string "zugesicherter Speicher" in german localization to "Speicher", as the word "zugesicherter" transports absolutely no information to the user.
This way all the interesting information about memory usage is visible without the need to resize the dialog.
CC AmineKhaldi