buildscript: update ForgeGradle to 1.2.2

To have toolchain support

build.gradle

@@ -27,7 +27,7 @@ buildscript {
         }
     }
     dependencies {
-        classpath 'com.github.TheElan:ForgeGradle:1.2.1'
+        classpath 'com.github.TheElan:ForgeGradle:1.2.2'
     }
 }