Prevent build from crashing when no Git or on Windows

app/build.gradle

@@ -20,11 +20,20 @@ repositories {
 }
 
 static def gitBranch() {
-    def branch = ''
-    def proc = 'git rev-parse --abbrev-ref HEAD'.execute()
-    proc.in.eachLine { line -> branch = line }
-    proc.err.eachLine { line -> println line }
-    proc.waitFor()
+    def branch = 'GitHub'
+    try {
+        def gitcheck = 'command -v git >/dev/null 2>&1'.execute()
+        gitcheck.waitFor()
+        if (gitcheck.exitValue() == 0) {
+            def proc = 'git rev-parse --abbrev-ref HEAD'.execute()
+            proc.in.eachLine { line -> branch = line }
+            proc.err.eachLine { line -> println line }
+            proc.waitFor()
+        }
+    } catch (Exception e) {
+        // Do nothing
+        println e
+    }
     branch
 }