Do not recalculate languiage settings when none are available

For optimisation Sloeber caches language settings.
However when the command failed (a list of 0 settings) Sloeber
recalculated these settings.
This was done to allow to refresh the cache however it does cause a
performance hit.
Therefore I opted to accept no results as a valid result untill a better
method is found.

Author: jan

io.sloeber.autoBuild/src/io/sloeber/autoBuild/extensionPoint/providers/AutoBuildLanguageSettingsProvider.java

@@ -253,8 +253,9 @@ public List<ICLanguageSettingEntry> getSettingEntries(ICConfigurationDescription
 		if (discoveryCommand == null || discoveryCommand.isBlank()) {
 			return LanguageSettingsStorage.getPooledList(list);
 		}
+		discoveryCommand=discoveryCommand.trim();
 		 List<ICLanguageSettingEntry> cachedList=myDiscoveryCache.get(discoveryCommand);
-		if ( cachedList== null || cachedList.size()==0 ) {
+		if ( cachedList== null ) {
 			myDiscoveryCache.put(discoveryCommand, runForLanguage(languageId, discoveryCommand, autoConf,
 					autoConf.getProject(), new NullProgressMonitor()));
 		}