INSTALL.md: Remove trailing space

Reviewed-by: Todd Short <todd.short@me.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from #19960)

(cherry picked from commit 98663af)

INSTALL.md

@@ -244,8 +244,8 @@ and issue the following command.
 
     $ nmake install
 
-The easiest way to elevate the Command Prompt is to press and hold down 
-both the `<CTRL>` and `<SHIFT>` keys while clicking the menu item in the task menu.
+The easiest way to elevate the Command Prompt is to press and hold down both
+the `<CTRL>` and `<SHIFT>` keys while clicking the menu item in the task menu.
 
 The default installation location is