FELIX-4628 : [Jetty] Ignore empty string value for truststore. Apply patch from Dominique Pfister

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1622261 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/http/jetty/src/main/java/org/apache/felix/http/jetty/internal/JettyConfig.java b/http/jetty/src/main/java/org/apache/felix/http/jetty/internal/JettyConfig.java
index 1e5571c..6f2e6ec 100644
--- a/http/jetty/src/main/java/org/apache/felix/http/jetty/internal/JettyConfig.java
+++ b/http/jetty/src/main/java/org/apache/felix/http/jetty/internal/JettyConfig.java
@@ -304,7 +304,8 @@
 
     public String getTruststore()
     {
-        return getProperty(FELIX_TRUSTSTORE, null);
+        String value = getProperty(FELIX_TRUSTSTORE, null);
+        return value == null || value.trim().length() == 0 ? null : value;
     }
 
     public String getTruststoreType()