security-win32.sec-fixed test failed on Appveyor

https://ci.appveyor.com/project/DynamoRIO/dynamorio/builds/27974936
```
[00:18:18] test 53
[00:18:18] Start 53: code_api|security-win32.sec-fixed
[00:18:18]
[00:18:18] 53: Test command: C:\projects\dynamorio\build\build_debug-internal-64\bin64\drrun.exe "-s" "90" "-quiet" "-debug" "-use_dll" "C:/projects/dynamorio/build/build_debug-internal-64/lib64/debug/dynamorio.dll" "-exit0" "-stderr_mask" "0xC" "-msgbox_mask" "0" "-dumpcore_mask" "0x7d" "-staged" "-code_api" "--" "C:/projects/dynamorio/build/build_debug-internal-64/suite/tests/bin/security-win32.sec-fixed.exe"
[00:18:18] 53: Test timeout computed to be: 600
[00:18:18] 53: error loading library security-win32.sec-fixed.dll.dll
[00:18:18] 52: in fixed dll
[00:18:18] 52: loaded security-win32.secalign-fixed.dll.dll
[00:18:18] 53: cmd.exe as data
[00:18:18] 53: calc.exe as data and no resolve
[00:18:18] 53: rundl32.exe as no resolve
[00:18:18] 53: done
[00:18:18] 53/230 Test #53: code_api|security-win32.sec-fixed ............................***Failed Required regular expression not found.Regex=[^in fixed dll
[00:18:18] ?
[00:18:18] loaded security-win32\.sec-fixed\.dll\.dll
[00:18:18] ?
[00:18:18] cmd\.exe as data
[00:18:18] ?
[00:18:18] calc\.exe as data and no resolve
[00:18:18] ?
[00:18:18] rundl32\.exe as no resolve
[00:18:18] ?
[00:18:18] done
[00:18:18] ?
[00:18:18] $
[00:18:18] ] 0.70 sec
```

Start with the Appveyor build log and the code_api|security-win32.sec-fixed test output in issue #3880. Investigate why the observed output says "in fixed dll" while the expected regular expression requires "loaded security-win32.sec-fixed.dll.dll". Done means the test passes consistently on the affected Windows/Appveyor configuration.

Written by the indexing model from the issue text.