base-files: fix manger->manager typo

It was reported, that a small typo sneaked in, so lets fix it.

Reported-by: @dave14305
Fixes: c19c31f7aa6f ("base-files: add migration information for APK")
Signed-off-by: Petr Štetiar <[email protected]>

package/base-files/files/etc/profile

@@ -42,7 +42,7 @@ fi
 if [ -x /usr/bin/apk ]; then
 cat << EOF
 
- OpenWrt recently switched to the "apk" package manger!
+ OpenWrt recently switched to the "apk" package manager!
 
  OPKG Command           APK Equivalent      Description
  ------------------------------------------------------------------