Fix nvram theme setting

Themes with blank spaces in the middle was not possible. This commit fix it by quoting the string passed to nvrm

CloverApp/Clover/Extensions.swift

@@ -30,6 +30,12 @@ extension String {
     return data
   }
   
+  /// - returns: A  quoted string for nvram
+  var nvramString: String {
+    return "'\(self)'"
+  }
+  
+  
   /// - returns: Bool value indicating that our string start with the same prefix ignoring casing.
   func hasPrefixIgnoringCase(_ str: String) -> Bool {
     return self.lowercased().hasPrefix(str.lowercased())

CloverApp/Clover/SettingsView.swift

@@ -943,9 +943,9 @@ final class SettingsViewController:
     
     if nvramValue != theme {
       if theme.count == 0 {
-        deleteNVRAM(key: key)
+        deleteNVRAM(key: key.nvramString)
       } else {
-        setNVRAM(key: key, stringValue: theme)
+        setNVRAM(key: key, stringValue: theme.nvramString)
       }
     } else {
       return