Fix NLS warning

Author: jan

io.sloeber.core/src/io/sloeber/core/Messages.java

@@ -118,6 +118,7 @@ public class Messages extends NLS {
 	public static String CompileDescription_WarningsDefault;
 	public static String CompileDescription_WarningsMore;
 	public static String CompileDescription_WarningsNone;
+	public static String SloeberConfiguration_Failed_Modify_config_rename;
 	public static String SloeberProject_Project_is_null;
 
     static {

io.sloeber.core/src/io/sloeber/core/internal/SloeberConfiguration.java

@@ -793,7 +793,7 @@ private boolean updateSourceEntries() {
 				getAutoBuildDesc().getCdtConfigurationDescription().setSourceEntries(newSourceEntries);
 
 			} catch (Exception e) {
-				Activator.log(new Status(IStatus.ERROR, CORE_PLUGIN_ID, "Failed to modify configuration for rename", e));
+				Activator.log(new Status(IStatus.ERROR, CORE_PLUGIN_ID, Messages.SloeberConfiguration_Failed_Modify_config_rename, e));
 			}
 			return true;
 		}

io.sloeber.core/src/io/sloeber/core/messages.properties

@@ -91,4 +91,5 @@ CompileDescription_WarningsCustom=Custom
 CompileDescription_WarningsDefault=Default
 CompileDescription_WarningsMore=More
 CompileDescription_WarningsNone=None
+SloeberConfiguration_Failed_Modify_config_rename=Failed to modify configuration for rename
 SloeberProject_Project_is_null=The provided project is null. Sloeber can not upgrade.