Update-I think I fixed it. Went to dll-files.com and downloaded httpapi 32bit file, extracted it to the winsxs/httpapi folder, and it replaced the dll. Re-ran sfc /scannow, and it said it is repaired. Ran sfc /scannow again, and no integrity violations found. Ran SFCFix, and no corruptions or other problems detected. So for now, all seems well. Not sure what programs would have used the corrupted file in the first place, since I never got any error messages.