Fix use of glob in beforePackHook, as glob has lost its observer

parameter in favour of a promise return.

gui-js/beforePackHook.js

@@ -2,15 +2,14 @@ let glob=require('glob');
 exports.default = async function(context) {
   let p=context.packager;
   // if libravel is present in dynamic_libraries, this is a ravel build.
-  glob.glob(p.info.projectDir+"/dynamic_libraries/libravel.*",function(er,files)
-       {
-         if (files.length>0)
-         {
-           p.appInfo.productName="ravel";
-           p.appInfo.sanitizedProductName="ravel";
-           p.appInfo.productFilename="ravel";
-           if (p.platform.name==="windows")
-             p.platformSpecificBuildOptions.icon="apps/minsky-electron/src/assets/RavelLogo.ico"
-         }
-       });
+  let files=glob.globSync(p.info.projectDir+"/dynamic_libraries/libravel.*")
+  if (files.length>0)
+  {
+    console.log('updating appInfo');
+    p.appInfo.productName="ravel";
+    p.appInfo.sanitizedProductName="ravel";
+    p.appInfo.productFilename="ravel";
+    if (p.platform.name==="windows")
+      p.platformSpecificBuildOptions.icon="apps/minsky-electron/src/assets/RavelLogo.ico"
+  }
 }