only have a single proxy password, regardless of account name, address, etc; only attempt to grab it from the keychain when both the "enable proxy" and "enable proxy authorization" checks are enabled

macosx/PrefsController.h

@@ -60,6 +60,7 @@
     IBOutlet NSTextField * fProxyAddressField, * fProxyPasswordField;
     IBOutlet NSPopUpButton * fProxyTypePopUp;
     NSString * fProxyPassword;
+    BOOL fProxyPasswordSet;
     
     IBOutlet NSTextField * fRPCPortField;
     IBOutlet NSTableView * fRPCAccessTable;