[LyX/master] Fixup 1b2aad9 : Cleanup of spacing in mathed

[Richard Heck]

commit d30fe45f4c721bb9fe4d750fba127ddd6652e95a
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Wed May 25 15:14:18 2016 +0200

    Fixup 1b2aad9 : Cleanup of spacing in mathed
    
    Now that 5mu are added on each side of : (because it is a relation), there 
is no need to do the same in the definition of \vcentcolon.
    
    This is closer to what is done in mathtools.sty.

diff --git a/lib/symbols b/lib/symbols
index 6106b46..279e64e 100644
--- a/lib/symbols
+++ b/lib/symbols
@@ -1103,7 +1103,7 @@ pod                lyxblacktext  0   0 func     x     
amsmath
 
 
 # mathtools.sty
-\def\vcentcolon{\kern4mu:\kern3mu}             mathtools
+\def\vcentcolon{:}                             mathtools
 \def\dblcolon{\vcentcolon\kern-8mu\vcentcolon} mathtools
 \def\coloneqq{\vcentcolon\kern-7mu=}           mathtools
 \def\Coloneqq{\dblcolon\kern-7mu=}             mathtools