Update one last expectation from gamma change.

expectations/gm/Test-Win7-ShuttleA-HD2000-x86-Release/expected-results.json

 {
   "expected-results": {
     "3x3bitmaprect_565.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           9785004568147979273
         ]
       ], 
       "bugs": [
@@ skipping 12475 matching lines @@
           "bitmap-64bitMD5", 
           4297052245541539817
         ]
       ], 
       "reviewed-by-human": true
     }, 
     "verttext_gpu.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          12922216189963810918
+          10328327575992025287
         ]
       ], 
       "reviewed-by-human": true
     }, 
     "verttext_pdf-poppler.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           13665505434076673485
         ]
@@ skipping 154 matching lines @@
           15843716056234692659
         ]
       ], 
       "bugs": [
         2146
       ], 
       "reviewed-by-human": false
     }
   }
 }