Merge r1716940, r1717086 from trunk:

Use 'ap_pbase64decode' to simplify code.

Silent a sparse Warning.

cid->ecb->lpszLogData can not be NULL.
It is defined in mod_isapi.h as:
typedef struct EXTENSION_CONTROL_BLOCK {
...
    char           lpszLogData[80];
...
Submitted by: jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1718332 13f79535-47bb-0310-9956-ffa450edef68