Fixed build breakage due to the use of undefined variable

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpasyncclient/trunk@1697867 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/httpasyncclient-cache/pom.xml b/httpasyncclient-cache/pom.xml
index 56d06cd..8574841 100644
--- a/httpasyncclient-cache/pom.xml
+++ b/httpasyncclient-cache/pom.xml
@@ -83,7 +83,6 @@
       <plugin>
         <groupId>org.apache.rat</groupId>
         <artifactId>apache-rat-plugin</artifactId>
-        <version>${hc.rat.version}</version>
         <executions>
           <execution>
             <phase>verify</phase>
diff --git a/httpasyncclient-osgi/pom.xml b/httpasyncclient-osgi/pom.xml
index 9aa5971..6ec73b4 100644
--- a/httpasyncclient-osgi/pom.xml
+++ b/httpasyncclient-osgi/pom.xml
@@ -136,7 +136,6 @@
       <plugin>
         <groupId>org.apache.rat</groupId>
         <artifactId>apache-rat-plugin</artifactId>
-        <version>${hc.rat.version}</version>
         <executions>
           <execution>
             <phase>verify</phase>
diff --git a/httpasyncclient/pom.xml b/httpasyncclient/pom.xml
index b42c713..deaf219 100644
--- a/httpasyncclient/pom.xml
+++ b/httpasyncclient/pom.xml
@@ -90,7 +90,6 @@
       <plugin>
         <groupId>org.apache.rat</groupId>
         <artifactId>apache-rat-plugin</artifactId>
-        <version>${hc.rat.version}</version>
         <executions>
           <execution>
             <phase>verify</phase>