runtime(doc): update :call with a range and remove space

Commit fc3c204 introduced a spurious space with the
:call command

Signed-off-by: Christian Brabandt <[email protected]>

Author: chrisbra

runtime/doc/usr_41.txt

@@ -1587,7 +1587,7 @@ once for every line in the range, with the cursor in that line.  Example: >
 
 If you call this function with: >
 
-	:10,15 call Number()
+	:10,15call Number()
 
 The function will be called six times, starting on line 10 and ending on line
 15.