title: Issue with CALDB -- NICER data processing
body: <p>I've been working on processing NICER data on my ubuntu, and I've been having some issues with CALDB. I'm trying to work with the remote access CALDB (<a href="https://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/caldb_remote_access.html" rel="nofollow noreferrer">1</a>) but can't seem to get it to work. Here's the string of errors that come up after I've executed</p>
  <p><em>heainit</em></p>
  <p><em>nicerl2 indir=/home/[user]/w3browse-319801/1050360102 clobber = yes</em></p>
  <p>in terminal.</p>
  <p>Error message:</p>
  <pre><code>ERROR: CALDB MPU_GAIN file query failed at /home/[user]/heasoft-6.27.2/x86_64-pc-linux-gnu-libc2.31/bin/nicerpi line 222.
  Dumping CFITSIO error stack:
  --------------------------------------------------
  ERROR ftp_status wants 331  but got 550
  Server is requesting SSL, will switch to ftps (ftp_file_exist)
  ERROR: This CFITSIO build was not compiled with the libcurl library package
  and therefore it cannot perform HTTPS or FTPS connections.
  Unable to read ftps file into memory (ftps_open)
  failed to find or open the following file: (ffopen)
  ftp://legacy.gsfc.nasa.gov/data/nicer/xti/caldb.indx
  CFITSIO error stack dump complete.
  Fail to select CALDB file with the given criteria (at HDgtcalf.c: 142)
  Unable to open CALDB index file (at HDgtcalf.c: 202)
  CFITSIO ERROR FILE_NOT_OPENED: could not open the named file
  Task nicerpi 1.24 terminating with status 104
  ERROR: fast event calibration failed at /home/[user]/heasoft-6.27.2/x86_64-pc-linux-gnu-libc2.31/bin/nimpucal line 206.
  Task nimpucal 1.8 terminating with status -1
  Warning: something's wrong at /home/[user]/heasoft-6.27.2/x86_64-pc-linux-gnu-libc2.31/bin/nimpucal line 33.
  ERROR: MPU0 calibration failed at /home/[user]/heasoft-6.27.2/x86_64-pc-linux-gnu-libc2.31/bin/nicercal line 291.
  Task nicercal 1.7 terminating with status -1
  ERROR: task nicercal failed at /home/[user]/heasoft-6.27.2/x86_64-pc-linux-gnu-libc2.31/bin/nicerl2 line 299.
  Task nicerl2 1.12 terminating with status -1
  </code></pre>
  <p>Thanks so much!</p>