adding thermal lens as default to design file

pykat/ifo/aligo/files/design.kat

@@ -230,7 +230,7 @@ bs2 BSAR2 50u 0 0 29.195 nBSi4 dump15 nSRBS dump16
 # Distance from beam splitter to Y arm input mirror
 s ly1 5.0126 nYBS nITMY1a
 
-lens ITMY_lens $SLY_f nITMY1a nITMY1b
+lens ITMY_lens $TLY_f nITMY1a nITMY1b
 s sITMY_th2 0 nITMY1b nITMY1
 
 # Y arm input mirror
@@ -259,7 +259,7 @@ attr ITMY mass 40
 # Distance from beam splitter to X arm input mirror 
 s lx1 4.993 nXBS nITMX1a
 
-lens ITMX_lens $SLX_f nITMX1a nITMX1b
+lens ITMX_lens $TLX_f nITMX1a nITMX1b
 s sITMX_th2 0 nITMX1b nITMX1
 
 # X arm input mirror
@@ -412,9 +412,6 @@ const fM 36.397884M
 const fP 54.596826M
 const TLY_f 34.5k         # Thermal lens ITMY
 const TLX_f 34.5k         # Thermal lens ITMX
-const SLY_f inf           # Substrate lens ITMY
-const SLX_f inf           # Substrate lens ITMX
-const th_f 34.5k
 ###########################################################################
 %%% FTend constants