Bump BORINGSSL_API_VERSION

We forgot to do this in
https://boringssl-review.googlesource.com/c/boringssl/+/99327, when
SSL_set_reject_unusable_ech_config was introduced.

Bug: 542983348, b:450001346
Change-Id: I98fab742617e58ced47d1d3e7f418e05a0e3f883
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/100907
Commit-Queue: David Benjamin <davidben@google.com>
Presubmit-BoringSSL-Verified: boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Benjamin <davidben@google.com>

include/openssl/base.h

diff --git a/include/openssl/base.h b/include/openssl/base.h
index 82d5a84..fec3237 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -73,7 +73,7 @@
 // A consumer may use this symbol in the preprocessor to temporarily build
 // against multiple revisions of BoringSSL at the same time. It is not
 // recommended to do so for longer than is necessary.
-#define BORINGSSL_API_VERSION 42
+#define BORINGSSL_API_VERSION 43
 
 #if defined(BORINGSSL_SHARED_LIBRARY)