examples: reduce number of jobs

Author: aabadie

examples/joblib_yarn_parallel.py

@@ -7,6 +7,6 @@
 
 if __name__ == '__main__':
     register_parallel_backend('yarn', YarnBackend)
-    with parallel_backend('yarn', n_jobs=10):
-        Parallel(n_jobs=10, verbose=100)(
+    with parallel_backend('yarn', n_jobs=1):
+        Parallel(verbose=100)(
             delayed(sqrt)(i**2) for i in range(100))