Fixed a slew of shutdown exceptions that arose due to improper or out-of-order resource clean-up, e.g. listeners, timers, executors.

Change-Id: I37c351c4202b32e92c076d9d566b96d7ff8d313a
diff --git a/core/net/src/main/java/org/onosproject/cfg/impl/ComponentConfigManager.java b/core/net/src/main/java/org/onosproject/cfg/impl/ComponentConfigManager.java
index b851776..2397c64 100644
--- a/core/net/src/main/java/org/onosproject/cfg/impl/ComponentConfigManager.java
+++ b/core/net/src/main/java/org/onosproject/cfg/impl/ComponentConfigManager.java
@@ -114,11 +114,8 @@
         String componentName = componentClass.getName();
         checkNotNull(componentName, COMPONENT_NULL);
         Map<String, ConfigProperty> cps = properties.remove(componentName);
-        if (cps != null) {
+        if (clear && cps != null) {
             cps.keySet().forEach(name -> store.unsetProperty(componentName, name));
-        }
-
-        if (clear) {
             clearExistingValues(componentName);
         }
     }