Avoid raise/handle deadlocks

Can cause log flooding in some edge cases and isn't really needed any
longer. Use a proper conditional followed by an actual error handler.

node-daemon/pvcnoded/util/keepalive.py

@@ -661,8 +661,6 @@ def node_keepalive(logger, config, zkhandler, this_node):
                     zkhandler.read("base.config.migration_target_selector")
                     != config["migration_target_selector"]
                 ):
-                    raise
-            except Exception:
                     zkhandler.write(
                         [
                             (
@@ -671,6 +669,12 @@ def node_keepalive(logger, config, zkhandler, this_node):
                             )
                         ]
                     )
+            except Exception:
+                logger.out(
+                    "Failed to set migration target selector in Zookeeper",
+                    state="e",
+                    prefix="main-thread",
+                )
 
     # Set the upstream IP in Zookeeper for clients to read
     if config["enable_networking"]:
@@ -680,11 +684,15 @@ def node_keepalive(logger, config, zkhandler, this_node):
                     zkhandler.read("base.config.upstream_ip")
                     != config["upstream_floating_ip"]
                 ):
-                    raise
-            except Exception:
                     zkhandler.write(
                         [("base.config.upstream_ip", config["upstream_floating_ip"])]
                     )
+            except Exception:
+                logger.out(
+                    "Failed to set upstream floating IP in Zookeeper",
+                    state="e",
+                    prefix="main-thread",
+                )
 
     # Get past state and update if needed
     if debug: