git-gui: Remove unnecessary reshow of blamed commit

Because we no longer redraw colors every time we select a particular
commit there is no need to redraw the screen after we get a new commit
in from blame --incremental.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/blame.tcl

@@ -354,12 +354,6 @@ method _read_blame {fd} {
 					$w_cgrp insert $lno.0 "|\n"
 				}
 			}
-
-			set hc $highlight_commit
-			if {$hc ne {}
-				&& [expr {$order($hc) + 1}] == $order($cmit)} {
-				_showcommit $this $highlight_line
-			}
 		} elseif {[regexp {^([a-z-]+) (.*)$} $line line key data]} {
 			set header($r_commit,$key) $data
 		}