don't compile if no sol extension

src/app/tabs/compileTab/compileTab.js

@@ -35,7 +35,8 @@ class CompileTab {
     this.fileManager.saveCurrentFile()
     this.editor.clearAnnotations()
     var currentFile = this.config.get('currentFile')
-    if (!currentFile && !/.(.sol)$/.exec(currentFile)) return
+    if (!currentFile) return
+    if (!/\.sol$/.exec(currentFile)) return
     // only compile *.sol file.
     var target = currentFile
     var sources = {}