use memlib call dll proc face nil access

[bung]

<https://github.com/bung87/webview2/blob/d51e6bba84aef345be8447a4e2ba9f317e437ad6/src/webview2/browser.nim#L52>
    
    
    Traceback (most recent call last)
    C:\Users\crc32\Documents\nim_works\webview2\src\webview2.nim(144) webview2
    C:\Users\crc32\Documents\nim_works\webview2\src\webview2.nim(70) 
webview_init
    C:\Users\crc32\Documents\nim_works\webview2\src\webview2.nim(23) wndproc
    C:\Users\crc32\Documents\nim_works\webview2\src\webview2\browser.nim(55) 
embed
    C:\Users\crc32\.nimble\pkgs\memlib-1.2.0\memlib.nim(1029) 
CreateCoreWebView2EnvironmentWithOptions
    SIGSEGV: Illegal storage access. (Attempt to read from nil?)
    
    
    
    Run

the traceback end in memlib.nim , I have no clue what is nil.