reduce occurrence of warning when unnecessary

build.xml

@@ -2621,6 +2621,7 @@ ignoreSetupDownloadErrors=true
                             <not>
                                 <contains string="@{file.path.name}" substring="slideshow." />
                             </not>
+                            <equals arg1="@{file.path.name}" arg2=""/>
                         </and>
                         <then>
                             <echo>Warning: no parent scene determined for script, additional false-positive errors may be flagged</echo>
@@ -2635,6 +2636,9 @@ ignoreSetupDownloadErrors=true
                         <not>
                             <contains string="@{file.path.name}" substring="slideshow." />
                         </not>
+                        <not>
+                            <equals arg1="@{file.path.name}" arg2=""/>
+                        </not>
                     </and>
                     <then>
                         <echo>jslint  @{file.path.name}</echo>