runtime(doc): trailing whitespace in options.txt, delete it.

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 38eb31d..b163571 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3633,7 +3633,7 @@
 	one dot may appear.
 	This option is not copied to another buffer, independent of the 's' or
 	'S' flag in 'cpoptions'.
-	Only alphanumeric characters, '-' and '_' can be used (and a '.' is 
+	Only alphanumeric characters, '-' and '_' can be used (and a '.' is
 	allowed as delimiter when combining different filetypes).
 
 						*'fillchars'* *'fcs'*