core: sqlite checkpoint tweaks. Switch the periodic checkpoint to passive mode. Truncate mode was painful on mobile. I'm seeing it succeed often enough that we don't grow indefinitely. Also fix the print.

src/ssb.tests.c

@@ -1532,11 +1532,7 @@ static char* _subprocess_check_output(const char* command)
 
 static bool _isspace(char c)
 {
-	return
-		c == ' ' ||
-		c == '\t' ||
-		c == '\r' ||
-		c == '\n';
+	return c == ' ' || c == '\t' || c == '\r' || c == '\n';
 }
 
 static char* _trim(char* p)