[chrome-gnome-shell] cmake: fixed build error introduced in commit 23be4096

[Yuri Konotopov <ykonotopov src gnome org>]

commit f6d3cc32580c80f30d844984f58bcea2854aa184
Author: Yuri Konotopov <ykonotopov gnome org>
Date:   Tue Apr 10 23:36:53 2018 +0400

    cmake: fixed build error introduced in commit 23be4096

 CMakeLists.txt |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/CMakeLists.txt b/CMakeLists.txt
index caa02b5..133d2be 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -99,7 +99,7 @@ if(BUILD_EXTENSION OR BUILD_CONNECTOR)
        execute_process(COMMAND echo "${CHROME_EXTENSION_KEY}"
                        COMMAND ${BASE64_EXECUTABLE} -d
                        COMMAND ${SHA256SUM_EXECUTABLE}
-                       COMMAND ${HEAD_EXECUTABLE} -c32
+                       COMMAND ${GHEAD_EXECUTABLE} -c32
                        COMMAND ${TR_EXECUTABLE} 0-9a-f a-p
                        OUTPUT_VARIABLE CHROME_EXTENSION_ID)
        message(STATUS "Calculated Chrome extension id: ${CHROME_EXTENSION_ID}")
@@ -107,7 +107,7 @@ if(BUILD_EXTENSION OR BUILD_CONNECTOR)
        execute_process(COMMAND echo "${OPERA_EXTENSION_KEY}"
                        COMMAND ${BASE64_EXECUTABLE} -d
                        COMMAND ${SHA256SUM_EXECUTABLE}
-                       COMMAND ${HEAD_EXECUTABLE} -c32
+                       COMMAND ${GHEAD_EXECUTABLE} -c32
                        COMMAND ${TR_EXECUTABLE} 0-9a-f a-p
                        OUTPUT_VARIABLE OPERA_EXTENSION_ID)
        message(STATUS "Calculated Opera extension id: ${OPERA_EXTENSION_ID}")