Add missing file to regressionfiles.txt (#165)

Author: shivupa

regressionfiles.txt

@@ -280,6 +280,7 @@ Gaussian/Gaussian16/output.txt.issue754.log
 Gaussian/Gaussian16/issue851.log
 Gaussian/Gaussian16/issue962.log
 Gaussian/Gaussian16/issue1153.log
+Gaussian/Gaussian16/water.log
 Gaussian/Gaussian16/C01_CC.log
 Gaussian/Gaussian98/C_bigmult.log
 Gaussian/Gaussian98/NIST_CCCBDB_1himidaz_m21b0.out