Update lmn_pre_install.rst - Defective URL

Line break in the URL of the download source leads to an error during copy&paste.

source/installation/install-from-scratch/lmn_pre_install.rst

@@ -196,8 +196,7 @@ Lade das lmn-appliance Skript herunter und setze die Ausführungsberechtigung:
 
 .. code-block:: Bash
   
-   wget https://raw.githubusercontent.com/linuxmuster/linuxmuster-prepare/master/   
-   lmn-appliance
+   wget https://raw.githubusercontent.com/linuxmuster/linuxmuster-prepare/master/lmn-appliance
    chmod +x lmn-appliance
 
 Aufruf lmn-appliance