Change stevedore repo to public (cherry-pick unity-master merge #1154)

Author: ashwinimurt

external/buildscripts/buildDependencies.txt

@@ -41,7 +41,7 @@ repo: public
 
 name : automake-src
 id : automake-src/1.16.1_d281b950e26265f55f0a63188a8c6388e638b354b7ed80d186690119cbc4f953.7z
-repo: testing
+repo: public
 
 name : autoconf-src 
 id : autoconf-src/2.69_0e4ba7a0363c68ad08a7d138b228596aecdaea68e1d8b8eefc645e6ac8fc85c7.7z