[bananas] Warning on Fedora version 25

[Eric Greisen]

One of our sites changed their OS from Fedora 24 to Fedora 25. 
Immediately various AIPS tasks (using old, unchanged load modules) began 
to produce NaNs.  The results of multiple executions, even using 
different versions of AIPS, were always the same, just wrong.  In fact, 
a beam from IMAGR looks much like parts of the FFT were not done but 
also contains horizontal stripes of NaNs - the image however appeared to 
be correct.  CCRES also produced NaNs and it is not a high-I/O demanding 
task like IMAGR.

Recommendation - do NOT install Fedora version 25.

Eric Greisen