[Bug 40709] iexplore crashes when proxy enabled

https://bugs.winehq.org/show_bug.cgi?id=40709

--- Comment #4 from Bruno Jesus  ---
This was also detected by Coverity.

*** CID 1362146:  Null pointer dereferences  (FORWARD_NULL)
/home/amine/wine/dlls/wininet/http.c: 1773 in HTTP_ShouldBypassProxy()
1767         while(1) {
1768             LPCWSTR tmp = ptr;
1769
1770             ptr = strchrW( ptr, ';' );
1771             if (!ptr)
1772                 ptr = strchrW( tmp, ' ' );
> > > CID 1362146:  Null pointer dereferences  (FORWARD_NULL)
> > > Comparing "ptr" to null implies that "ptr" might be null.

1773             if (!ptr)
1774                 ptr = tmp + strlenW(ptr);
1775             ret = HTTP_DomainMatches( server, substr(tmp, ptr-tmp) );
1776             if (ret || !*ptr)
1777                 break;
1778             ptr++;