contrib/ci.inria.fr: only run basic pipeline every hour

contrib/ci.inria.fr/Jenkinsfile-basic

@@ -1,7 +1,7 @@
 #!groovy
 // StarPU --- Runtime system for heterogeneous multicore architectures.
 //
-// Copyright (C) 2018                                CNRS
+// Copyright (C) 2018, 2019                          CNRS
 //
 // StarPU is free software; you can redistribute it and/or modify
 // it under the terms of the GNU Lesser General Public License as published by
@@ -24,8 +24,8 @@ pipeline
 	// Trigger the build
 	triggers
 	{
-		// Poll gforge explicitly every 15mn
-		pollSCM('00-59/15 * * * *')
+		// Poll gforge explicitly every hour
+		pollSCM('0 * * * *')
 	}
 
 	stages

contrib/ci.inria.fr/Jenkinsfile-bsd

@@ -1,7 +1,7 @@
 #!groovy
 // StarPU --- Runtime system for heterogeneous multicore architectures.
 //
-// Copyright (C) 2018                                CNRS
+// Copyright (C) 2018, 2019                          CNRS
 //
 // StarPU is free software; you can redistribute it and/or modify
 // it under the terms of the GNU Lesser General Public License as published by
@@ -24,8 +24,8 @@ pipeline
 	// Trigger the build
 	triggers
 	{
-		// Poll gforge explicitly every hour
-		pollSCM('00 * * * *')
+		// Poll gforge explicitly every past-half hour
+		pollSCM('30 * * * *')
 	}
 
 	stages