Update DISTRIBUTING.md

Author: PallHaraldsson

DISTRIBUTING.md

@@ -106,7 +106,7 @@ Note that if you want your `.app` to be able to run on OSX 10.6 Snow
 Leopard, you must pass `USE_SYSTEM_LIBUNWIND=1` as one of the make
 variables passed to both `make` processes.  This disables the use of
 `libosxunwind`, a more modern libunwind that relies on OS features
-available only in 10.7+.  This is the reason why we support 10.7+ [while we did support 10.6 prior to Julia 0.3.0](http://julialang.org/downloads/platforms.html).
+available only in 10.7+.  This is the reason why we support 10.7+ [while we did support 10.6 prior to Julia 0.3.0](http://julialang.org/downloads/platform.html).
 
 Windows
 -------