[FIX] Bundling: Dynamic preload calls should not emit warnings

The UI5 core library contains dynamic calls to sap.ui.require.preload.
Those calls should not result into a warning in the build log, as they
are correct and should just be skipped.

This has been introducted with #341.

lib/lbt/analyzer/JSModuleAnalyzer.js

@@ -607,7 +607,7 @@ class JSModuleAnalyzer {
 					info.addSubModule(moduleName);
 				});
 			} else {
-				log.warn("Cannot evaluate registerPreloadedModules: '%s'", modules && modules.type);
+				log.verbose("Cannot evaluate registerPreloadedModules: '%s'", modules && modules.type);
 			}
 		}