update opnelane gf180 base config.tcl

~ set min rt layer to Metal1
- remove redundant detailed router min layer
+ set TECH_LEF_MIN and TECH_LEF_MAX for multicorner extraction

gf180mcu/openlane/config.tcl

diff --git a/gf180mcu/openlane/config.tcl b/gf180mcu/openlane/config.tcl
index 8cab9bd..d17f8be 100644
--- a/gf180mcu/openlane/config.tcl
+++ b/gf180mcu/openlane/config.tcl
@@ -22,7 +22,9 @@
 set ::env(LIB_TYPICAL) $::env(LIB_SYNTH)
 
 # Technology LEF
-set ::env(TECH_LEF)  [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/techlef/*.tlef"]
+set ::env(TECH_LEF) [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/techlef/*.tlef"]
+set ::env(TECH_LEF_MIN)  [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/techlef/*.tlef"]
+set ::env(TECH_LEF_MAX)  [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/techlef/*.tlef"]
 set ::env(CELLS_LEF) [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/lef/*.lef"]
 set ::env(GDS_FILES) [glob "$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/gds/*.gds"]
 set ::env(STD_CELL_LIBRARY_CDL)	"$::env(PDK_ROOT)/$::env(PDK)/libs.ref/$::env(STD_CELL_LIBRARY)/cdl/$::env(STD_CELL_LIBRARY).cdl"
@@ -103,9 +105,8 @@
 
 # Routing
 set ::env(METAL_LAYER_NAMES) "Metal1 Metal2 Metal3 Metal4 Metal5"
-set ::env(RT_MIN_LAYER) "Metal2"
+set ::env(RT_MIN_LAYER) "Metal1"
 set ::env(RT_MAX_LAYER) "Metal5"
-set ::env(DRT_MIN_LAYER) "Metal1"
 set ::env(GRT_LAYER_ADJUSTMENTS) "0,0,0,0,0"
 
 ## Tracks info