Avoid a crash when attempting to change password

In some cases we could keep stack garbage in a local pointer
variable until the cleanup at the end of the function wherein
krb5_free_context() would choke on the invalid non-NULL value.
Initialize to zero to avoid the issue (should be written as NULL
but stick to the prevailing style).

ticket: 7329 (new)
queue: kfw
target_version: 1.10.4
tags: pullup

src/windows/leash/LeashView.cpp

@@ -1034,7 +1034,7 @@ VOID CLeashView::OnMakeDefault()
 
 VOID CLeashView::OnChangePassword()
 {
-    krb5_context ctx;
+    krb5_context ctx = 0;
     krb5_ccache ccache = 0;
     krb5_principal princ = 0;
     char *pname = NULL;