Reverted README file deletion and added comment for dynamic library

deps/libssl/README.md

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+In ProxySQL 2.0.4 , libssl was upgrade from 1.1.0h to 1.1.1b .
+
+In ProxySQL 2.0.7 , libssl was downgraded back to 1.1.0h . See [bug 2244](https://github.com/sysown/proxysql/issues/2244) .
+
+In ProxySQL 2.1.1 , libssl was upgraded to version 1.1.1j
+
+In ProxySQL 2.4.0 , libssl was upgraded from version 1.1.1j to 3.0.2
+
+In ProxySQL 2.4.8 , libssl was upgraded from version 3.0.2 to 3.0.8
+
+In ProxySQL 2.5.x , libssl was upgraded from version 3.0.8 to 3.1.0
+
+
+Do not upgrade without extensive testing.
+
+See note about `struct bio_st` in MySQL_Data_Stream.cpp .
+
+Run `verify-bio_st-match.sh` to confirm compatibility.
+
+In ProxySQL 3.0.1, OpenSSL was changed from being statically linked to dynamically linked.