Revert "tdf#99589 tolower changed to rtl::toAsciiLowerCase"

Following Stephan's message https://gerrit.libreoffice.org/#/c/32462/

This reverts commit 47f338c1.

Change-Id: I6846fe495a9e1cccce56a2764c61b804c0eaa75c
Reviewed-on: https://gerrit.libreoffice.org/32637Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Tested-by: Julien Nabet <serval2412@yahoo.fr>

setup_native/source/win32/wintools/msimsp/msimsp.c

@@ -9,7 +9,6 @@
 
 #include <stdio.h>
 #include <sys/stat.h>
-#include <rtl/character.hxx>
 
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
@@ -45,7 +44,7 @@ int main(int argc, char *argv[])
     /* Get parameters */
     while (argv[1] && (argv[1][0] == '-' || argv[1][0] == '/'))
     {
-        switch(rtl::toAsciiLowerCase(argv[1][1]))
+        switch(tolower(argv[1][1]))
         {
         case 's':
             argv++; argc++;