AMBARI-8977. Unit test failue on CentOS 5.

ambari-metrics/ambari-metrics-host-monitoring/pom.xml

@@ -162,7 +162,7 @@
                 </goals>
                 <configuration>
                   <target name="psutils-compile">
-                    <exec dir="${basedir}/src/main/python/psutil" executable="python" failonerror="true">
+                    <exec dir="${basedir}/src/main/python/psutil" executable="${executable.python}" failonerror="true">
                       <arg value="setup.py" />
                       <arg value="bdist_egg" />
                       <arg value="--bdist-dir" />
@@ -211,7 +211,7 @@
                 </goals>
                 <configuration>
                   <target name="psutils-compile">
-                    <exec dir="${basedir}/src/main/python/psutil" executable="python" failonerror="true">
+                    <exec dir="${basedir}/src/main/python/psutil" executable="${executable.python}" failonerror="true">
                       <arg value="setup.py" />
                       <arg value="build" />
                       <arg value="--build-platlib" />