Check git hash/tag only if we are in git repo

Checking for git hash and tag from released source package
causes confusing "fatal" warning messages. Now do it only
if we are in a git repo.

Task-number: QTEE-338
Change-Id: I6269b22fd774f218cd9a219a4f2519d73bf13358
Reviewed-by: Rainer Keller <[email protected]>

Author: Samuli Piippo

appcontroller.pro

@@ -17,13 +17,15 @@ android {
 INSTALLS+=target
 
 # Find out git hash
-unix:system(which git):HAS_GIT=TRUE
-win32:system(where git.exe):HAS_GIT=TRUE
-contains(HAS_GIT, TRUE) {
-    GIT_HASH=$$system(git log -1 --format=%H)
-    !system(git diff-index --quiet HEAD): GIT_HASH="$$GIT_HASH-dirty"
-    GIT_VERSION=$$system(git describe --tags --exact-match)
-    isEmpty(GIT_VERSION) : GIT_VERSION="unknown"
+exists(.git) {
+    unix:system(which git):HAS_GIT=TRUE
+    win32:system(where git.exe):HAS_GIT=TRUE
+    contains(HAS_GIT, TRUE) {
+        GIT_HASH=$$system(git log -1 --format=%H)
+        !system(git diff-index --quiet HEAD): GIT_HASH="$$GIT_HASH-dirty"
+        GIT_VERSION=$$system(git describe --tags --exact-match)
+        isEmpty(GIT_VERSION) : GIT_VERSION="unknown"
+    }
 } else {
     GIT_HASH="unknown"
     GIT_VERSION="unknown"