[DOCS] Fixing broken "IDE setup" link in the Building Spark documentation.

The location of the IDE setup information has changed, so this just updates the link on the Building Spark page.

Author: Mike Dusenberry <dusenberrymw@gmail.com>

Closes #6467 from dusenberrymw/Fix_Broken_Link_On_Building_Spark_Doc and squashes the following commits:

75c533a [Mike Dusenberry] Fixing broken "IDE setup" link in the Building Spark documentation by pointing to new location.

docs/building-spark.md

@@ -176,7 +176,7 @@ Thus, the full flow for running continuous-compilation of the `core` submodule m
 # Building Spark with IntelliJ IDEA or Eclipse
 
 For help in setting up IntelliJ IDEA or Eclipse for Spark development, and troubleshooting, refer to the
-[wiki page for IDE setup](https://cwiki.apache.org/confluence/display/SPARK/Contributing+to+Spark#ContributingtoSpark-IDESetup).
+[wiki page for IDE setup](https://cwiki.apache.org/confluence/display/SPARK/Useful+Developer+Tools#UsefulDeveloperTools-IDESetup).
 
 # Running Java 8 Test Suites