Avoid printing confusing log entry when image version doesn't exist (#5060) (#3497)

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/5060.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+Avoid printing confusing (Compsoer version didn't match regexp) log entry when version is empty.
+```

google-beta/resource_composer_environment.go

@@ -1608,14 +1608,18 @@ func composerImageVersionDiffSuppress(_, old, new string, _ *schema.ResourceData
 		// Somehow one of the versions didn't match the regexp or didn't
 		// have values in the capturing groups. In that case, fall back to
 		// an equality check.
-		log.Printf("[WARN] Composer version didn't match regexp: %s", old)
+		if old != "" {
+			log.Printf("[WARN] Composer version didn't match regexp: %s", old)
+		}
 		return old == new
 	}
 	if newVersions == nil || len(newVersions) < 3 {
 		// Somehow one of the versions didn't match the regexp or didn't
 		// have values in the capturing groups. In that case, fall back to
 		// an equality check.
-		log.Printf("[WARN] Composer version didn't match regexp: %s", new)
+		if new != "" {
+			log.Printf("[WARN] Composer version didn't match regexp: %s", new)
+		}
 		return old == new
 	}