Reset data manager variables before running runPages

Fixes a problem where, if you decrypt the device, the promtp for
installing SuperSU appears briefly before it automatically
reboots without letting you confirm or deny.

Change-Id: I6f7b1c7096e788ccabd8f5aac9eb01d38bfbc0f7
diff --git a/gui/gui.cpp b/gui/gui.cpp
index 4465232..469beb6 100644
--- a/gui/gui.cpp
+++ b/gui/gui.cpp
@@ -588,6 +588,9 @@
 
 static int runPages(const char *page_name, const int stop_on_page_done)
 {
+	DataManager::SetValue("tw_page_done", 0);
+	DataManager::SetValue("tw_gui_done", 0);
+
 	if (page_name)
 		gui_changePage(page_name);
 
@@ -896,7 +899,6 @@
 		}
 	}
 #endif
-	DataManager::SetValue("tw_page_done", 0);
 	return runPages(page_name, stop_on_page_done);
 }